Below are useful links that may help. I have gone through similar problems as you. I have been trying to get my account corrected for over 3 years, although my case is more complicated as I went back to full time work after retirement. If you are going to pursue a Request for Consideration you will need to file Form SSA-561-U2 with your local SSA Office to appeal their decision.
I urge you to keep meticulous records of names, dates, your conversations, copies of any correspondence, and any SSA Office visits as I have found the SSA Bureaucracy can get complicated. I interpret these rules differently than SSA agents and I may be wrong so use my advice for what it's worth.
You are entitled to a Grace Year Special Monthly Earnings Limit Rule where only the months over the$1410 limit are subject to being withheld. Any " Earned Wages" the months before your retirement do not count in your Grace Year. After the Grace Year the annual limit of $1 for every $2 over the annual limit is in effect. When you reach you Full Retirement year another Special Rule is in effect.
All links attached should be SSA.gov sites. Please verify before clicking on them for your own safety. The
1807.6What is your benefit amount when the monthly earnings test applies?
When the monthly earnings test applies, regardless of the amount of annual earnings, you receive full benefits for any month that:
Your earnings do not exceed the monthly exempt amount; and
You do not perform substantial services in self-employment.
Note: Earnings for the entire year, i.e., January through December, are always used to determine the maximum amount we withhold from benefits if you are under FRA. However, the monthly test prevents us from withholding benefits for months that meet the above rules.
Here are other resources:
(What You Need to Know When You Get Retirement or Survivors Benefits):