FNB can't provide a proof of purchase, a simple request...

I have been trying to get a proof of purchase for an online transaction that was made on my credit card. I was on the line for 15 minutes, being transferred back and forth until the phone was dropped on me. I called back and went through the same tedious process, just to be told that I cannot get a proof of payment for a specific transaction and the only thing I can do is print out my entire statement. This is unacceptable. I do not want to send an entire statement as proof of ONE transaction. I asked for a letter but was told to visit a branch. Terrible service!! How can all other banks provide proof of payment, but FNB cannot?