Social Security Issues: Filed for Ss 62, Credits at Fra for Month"S Over Earnings Max W/No Benefit Paid

I started benefits at age 62 and continued working full time until 6 mos before FRA. According to what my local SSA office explained after printing out my benefit matrix by month, to show my benefit at every month during the 4 years to reaching FRA. Of those 48 month's the SSA paid me 16.6 month's of benefits. I am suppose to receive 31.6 mos of credits towards a higher benefit amount for the monthes I received reduced or no payments because of exceeding the income threshold after reaching FRA.
It has been 10 month's since attaining FRA and I have written many letters asking for my benefit recalculation and payments since FRA reflecting credits of the difference in those benefits after consideration for those month's credits.
According to my math, SS owes over $328 increased permanent benefits since March 2015.
my FRA. They came up with an OVERPAYMENT of $3200 they say they overpaid me, and have REDUCED my monthly benefit by $97 a month now.
What am I going to have to do about getting those credits for the monthes I did not receive any benefit added to my preliminary benefit and the CREDITS of those payments since reaching FRA? It has been over a month now with now reply to 2 priority mails I sent them.
Thank you, I hope I receive some PERTINANT answers to this dilemma.

Social Security Issues: Filed for Ss 62, Credits at Fra for Month"S Over Earnings Max W/No Benefit Paid