Payment date entered as 2012 needs changing to 2013!

A payment was entered as 5/6/12 and should have been 5/6/13.  This was not discovered until the middle of June during the monthly sales tax audit.  By then, a new invoice had been created for this client.

I called tech support and was told to create a "fake, new" invoice and apply a new payment again with the correct date.  

Am I missing something?  Wouldn't that skew the client totals in the reports?!  It would mess up taxes and income reporting too.

I said that it would show up on the client's statement, and was told to use "white-out".

Then tech support told me that we could reset the database back to 5/6/13 to fix it.  We have over 20 employees making at least 10 entries every day in Timeslips.  Does anyone else see the obvious problem with resetting the data base to a time over a MONTH earlier.. and through a billing cycle??

Tech support told me that all they could do was offer solutions, but not fix problems.

Seriously?

So... can anyone offer a better suggestion or solution to that single date problem?