PLease help..

I foolishly changed the name of one of my fave toons a few months back.

I now want to change it back to what it was originally, I know that the name does not become available again for 90 days. The problem I have, is that I don't know how long ago it was that I made the transaction, I think it's roughly 90 days but it doesn't show up on my transaction history in battle net account.

I purchased it on a pressie card that had been sitting in my wallet for ages so I can't check my bank statements either..

Can someone tell me if blizz have the ability to tell me when I made the name change (date).

Thanks in advance.