Amazon Sends Incorrect Invoice, Fails to Correct the Error

I recently bought something from Amazon, and to my surprise, they sent me the wrong bill. Even though I tried to get it fixed, the customer service reps kept brushing me off and saying that the invoice couldn't be changed. This isn't just a problem for me; my brother has also had the same thing happen with his purchases. We can't use the bad invoices, and sending back the items and reordering them at a higher price is not a good idea. Amazon is a well-known online store, so it's very disappointing that they won't fix this problem and send us the correct invoices. I'm asking Amazon to fix this problem right away by sending us invoices that are correct and reflect what we bought.