I just had this issue
https://forum-en.gw2archive.eu/forum/game/bltc/An-error-occurred-finalizing-your-purchase which send me here. I had the error after i already payed with a Paysafe card. So the credits on it are poof and i can not try it again.
Yes i already send a Ticket
No i have no patience.. (due the daily black friday sale
)
If its a upper and or lower case issue in the billing info.. either it should be resolved or put in as a notice after you select the payment method
now all i can do is wait for my gems to appear or get word (hopefully before the bank expension sale ends!)