ITunes billing error, no proper resolution ripoff Cupertino California

I bought an album on iTunes a few weeks ago, but was billed for the same album twice. The album cost me $16.99 and I had to pay it twice because of an error on Apple's part. I contacted them and they insisted that it was my fault, even thought it had all the characteristics of a billing error. I only have this album in my iTunes library once, not twice, but the record said I bought it twice.

They gave me a credit for the extra $16.99 that would appear in 5 business days. It's been almost two weeks and there is no credit, and the debit card I bought it with is now down due to a billing error.

I'm sure the credit will appear soon, but it's just the point that Apple wouldn't even have the decency to at least give a real refund since I am a college student and need a little extra money in case I need to buy an extra book for a course that was not announced until late or a similar need, and with the price of books, that $16.99 could have helped.

Esjeur
Private, Massachusetts
U.S.A.