Underpayments

Hello

I was reapproved for social security survivor benefits in February 2016.

In July 2016 I recieved my back payment it was supposed to be 17k but they only paid me 9k and withheld the rest claiming they overpaid me.

I appealed it within 60 days to prove the overpayments were not my fault, and they told me that they should not have withheld it because it was shown as having been waived.

Then they said they'd send a note of it to the payment center and they should fix it i.e. pay it within 60 days.

After that, none of it came, and I've called back quite a few times only to be told it could be 45 more days.

Now it's June 2017. Almost one whole year later and I still have not seen any of the money they withheld when they were supposed to pay me $17k but only paid $9k.

....what is my next move here, I've gotten no letters, and anything I called they said it could be 45 days.

Originally I was told it was shown as waived and it was a mistake on their part to withhold that money.

Whether I will actually see any of it or not, how can I get to the bottom of it? I need know what questions to ask!