I was charged twice for signing up on apple arcade even though I am under the 3-month free trial

I was charged TWICE for signing up on Apple Arcade even though i am on a 3-month free trial, the main problem is I haven’t received an invoice. I tried asking for a refund on their support but it won’t show up, it says that I didn’t purchase anything that is eligible for a refund. Can someone tell me how would i be able to get a refund without the invoice? I do have the reference number but it’s no use since the transaction won’t show up on their end