I can't report a problem on my accidental purchase.

I accidentally purchased a month of YouTube Red instead of the free trial. I contacted support through email and didn't get a reply within the 48 hour window. I also tried to report a problem on the receipt, but everytime I try, it says "We could not process this request." How can I report my accidental purchase? And should I say I accidentally purchased this item, or I meant to purchase a different item?