In its newsletters and magazines, in congressional testimony and on its website, AARP warns seniors about deceptive direct mail and other dubious marketing come-ons as part of its mission to protect members from financial abuses.

But the huge lobbying groupโ€™s own aggressive efforts to coax seniors to join or renew their memberships also have drawn a burst of criticism this year.

Angry members say AARPโ€™s barrage of solicitation letters and social media posts can mislead or confuse aging consumers, some of whom struggle with memory and managing their financial affairs. Hundreds have complained about getting false warnings that their memberships would soon expire, and at least some people have unwittingly paid for duplicate memberships.

The critics include Kathy Portie, senior editor of the Big Bear Grizzly weekly newspaper in Southern California. In January, she received a sponsored post from AARP in her Facebook feed that read: โ€œYour membership is about to expire. … ACT FAST โ€” Time is running out.โ€

Her terse reply, mirroring the grievances of dozens of others who received the same post, was, โ€œNo itโ€™s not. It is valid through 2020. So stop it.โ€

Wendi Fein fumes about the experience of her octogenarian parents, Ruth and Richard Schwartz. She said the two, who live in Nevada City, Calif., have cognitive issues but, like many in their generation, pay their bills promptly without asking questions.

In January, Fein wrote to the Better Business Bureau about discovering that her parents sent in a check to AARP each time they received a mailing last year โ€” five times in all.

โ€œEvery time,โ€ she said, โ€œthey paid the $16,โ€ which covers a membership for two.

The extra payments have since been refunded, Fein said, and the organization was asked twice by phone to stop hounding her parents. Even so, she said, the couple received another notice and wrote out yet another check that would have been mailed if her sister hadnโ€™t intercepted it.

โ€œFor an organization thatโ€™s primary goal is senior advocacy, their practice of multiple renewal notices is the antithesis of this goal,โ€ Fein wrote in her complaint to the Better Business Bureau.

Over the last three years, more than 425 complaints have been received by the Better Business Bureau and consumer help websites, or posted as comments on AARPโ€™s Facebook ads and online community forum. In the last three months alone, there have been more than 120 negative comments in response to AARP membership ads on Facebook. On AARPโ€™s community forum, the renewal practices have been criticized as โ€œdeceptive,โ€ โ€œa waste,โ€ โ€œstupidโ€ and โ€œan obscenity.โ€

AARP declined requests by FairWarning for an interview with a senior official to discuss complaints. Via email, AARP spokesman Josh Rosenblum said AARP has discontinued some of the social media language that has been criticized. He also said members who complain about multiple renewal notices will get a single mailing 30 days before the renewal deadline.

โ€œAARP is dedicated to listening to and caring for our 38 million members, but if an issue arises as it sometimes does, we take action to solve it and learn from it, which is why we have an A(plus) Better Business Bureau rating,โ€ Rosenblum wrote.

AARP is only one of the many membership groups, publishers and charities that bombard consumers with letters or online communications. Their reasoning is that โ€œsometimes, people donโ€™t see it the first time,โ€ said Ira S. Kalb, a marketing professor at the University of Southern California.

Still, Kalb said, an organization such as AARP has to be careful not to seem cavalier or irresponsible. โ€œIf itโ€™s to provide you with good service and itโ€™s time to update, thatโ€™s the positive side. If theyโ€™re taking advantage of elderly people, itโ€™s not good. … Their reputation is based on protecting the elderly.

Indeed, in its mission statement, AARP describes itself as a โ€œsocial welfare organizationโ€ that โ€œfights for the issues that matter most to families … such as health care, employment and income security, and protection from financial abuse.โ€ AARPโ€™s publications over the past year have warned readers about โ€œholiday shopping scamsโ€ as well as crooked car repair shops and technical support services.

But critics say the organization risks becoming just what it warns against with some of its appeals. In a recent email, Portie told FairWarning that โ€œAARP is supposed to be an organization that protects seniors from scams, but I feel itโ€™s hypocritical when they practice such questionable marketing tactics themselves.

โ€œWhy canโ€™t they say โ€˜Is your AARP membership about to expire?โ€™ rather than โ€˜Your AARP membership is about to expire.โ€™ Simple fix, right?โ€

Once known as the American Association of Retired Persons, and still mostly focused on members age 50 or older, AARP is a giant among membership groups and carries significant clout in Washington, D.C., and in states across the nation. The annual $16 membership charge provides subscriptions to the organizationโ€™s magazine and newsletter as well as shopping discounts.

AARP declined to say how many people might have inadvertently paid for multiple memberships by responding to repeated solicitations.

โ€œIโ€™m 92 and never know if I will make it through to the next year. However, after six months, I start getting mail saying my membership is about to expire,โ€ Agnes Schaefer of Livingston, Mont., said in a phone interview. โ€œYou can write and ask them not to and youโ€™re completely ignored. Iโ€™m furious with those people.โ€