Anonymous participant I'd upload as genuine a bank certificate/account statement and funds source (income deposits?) as possible along with a very brief cover letter describing your document and noting the ambiguity of the initial request, and your willingness to supply further documents. Make sure your bank documents have the account number and name on them.
You might want to clarify with the embassy whether or not they want the source of the funds being legitimate (how you got the money) or the statement itself.
If you need services at local immigration office and some eagle-eyed officer notices you missed your 90 report expect a 2000 baht fine. Other than that forget about it for now and report 90 days after your next entry
Sounds like an ad. Coupled with the earlier post this morning expressing reluctance to provide documentation and suddenly all the positive responses in a very short time... sceptical.