That's pretty vague from Sony. But when you filed the dispute with your bank what did the statement show as far as description and amount? Sony may be lumping multiple transactions together.
My suggestion would be to contact your bank and obtain transaction Id codes and reference id numbers for...
Seems these days companies get a bit too butthurt over a simple business transaction. I work in a credit card dispute/fraud dept at a bank and know my rights as a cardholder. I once disputed a transaction to a local guitar shop and received a call from the manager who proceeded to yell at me...