Authorization hold/double bill

I was billed twice for a single order. I immediately brought it to their attention, and I was told it was an authorisation hold and the money wasn't really deducted(falsified a report saying the transaction "failed"). But my bank statement begs to differ. I sent them the statement and now Im being told "Your authorization hold will expire within 30 days of the original transaction".

So they can instantaneously take my money...but when it comes to giving it back theres a 30 day delay!?! Nonesense!!!