They can’t add, but cut my benefits off

Before I retired in 2015 I checked THREE times to be sure how much SS I would receive because I couldn’t afford to retire without close budgeting.  In August of 2018, I received a letter that I’d been overpaid by about $15,000 and my monthly benefit would be reduced to its “correct” amount.   I appealed.  I received a lesser SS payment but no decision about my appeal.  In August of 2021 (3 years later) I received a letter saying I would receive $0 and that I would have to pay my Medicare out-of-pocket until my “debt” was repaid, approximately 2 years.  Since then I have received $0 benefits, which had been in 2018 over $700/month, AND have had to pay about $170/month for Medicare.