Xfinity prepaid gift card help!

Hi, I was issued a Xfinity prepaid MasterCard and I'm having issues using it to buy an Amazon gift card because I want to use the full balance of the gift card and I'm having issues using it. I've been trying to call 866-385-8392, but there is no way I can contact a human person and it is incredibly frustrating because I have spent multiple attempts trying to call this number without getting any sort of option to speak with a human person on what the issue with the card is. My card is fully activated, so I believe that the issue may be because the billing address on the gift card uses “Unit”, but every other merchant will auto-correct or will use the standard format as “Apt”. So that could be one reason, but I don't know why else it is not accepting this card to purchase a gift card. Can somebody help me troubleshoot the issues with using this gift card, please?