Not unless someone was injured severely enough to warrant medical attention. Otherwise the damages are limited to the price of the meal.

Any child support would have been paid - long ago - to the custodial parent and would never have been the property of the child.

You will have to do some research - either here or elsewhere - for local consumer protection attorneys and then make a few phone calls.

One does not file a lawsuit over the price of a pizza.

You can file a request for reconsideration or a request that the overpayment be waived depending on the facts of your case.

A local consumer protection attorney is where I would start.

If you were told there was an asset limit then you were not on SSDI. You were on SSI which is almost a type of welfare benefit for the disabled. ...

You'll have to do some research, either here or elsewhere, and make a few phone calls to local attorneys.

Certainly smells like a scam to me............

You waived doctor / patient privilege but your lawyer is still bound by the attorney / client privilege and cannot use that information in any way...