What alternative proof of income can US citizens provide for a retirement Non-Immigrant O visa in Thailand?

Hello All. We just saw this on Thai visa!!

We are a married couple, who are US citizens. We have been here on a "retirement, Non Immigrant O" visa, that we have renewed for 3 years now. For our proof of income, we always go to the US embassy to get a financial affidavit of our income. We cannot deposit all of our pension at once in a Thai bank, because we receive it monthly. Also, Social Security will not deposit payments into a Thai bank at all. Social Security also comes in monthly.

When we tried to show US bank statements before, they would not take them. So what form of proof can we use to show how much we make? (we are in Nakhon Si Thammarat)

We do have Thai bank accounts, but do not keep very much money in them, therefore do not have a history of adequate deposits.

TIA