It sounds like PayPal is asking you to prove you did not receive the cloud credits.
But what you should do is say you did not purchase cloud credits.
There is a difference between an unauthorized charge and goods not received.
OVH argued that the charge was a credit and not the service itself and that I still have the credit (hence, it was delivered).
Then I said that the reason should be charge unauthorized, as I canceled precisely because of the unexpected amount of the bill, and I didn't perform a credit. The reason switched mid claim.
PayPal finally said that I didn't prove I had credit on OVH, which is indeed confusing (meaning I didn't spend it?). If I didn't order it shouldn't matter what's on their platform.
If the order was canceled then how can it be claimed not received? The charge occurring on a canceled order is an unauthorized charge. I'd recommend to file that type of claim. They are different and OVH is being terse. It's something you can do before you call Saul.