Issues with in-game purchases

I’m trying to buy a gold upgrade purchase for my guns of glory game, when i go to purchase it says error purchasing contact apple.com/support/itunes/we/.

Nothing is wrong with my banking info visa debit because I have the available funds, and iTunes took out previous purchases just recently, then suddenly it won’t let me make any more purchases. Because of a problem with my apple account? Please figure out the issue thank you