buying gems failed

[mimimoo]

Hey my ingame name is bershi and i wanna buy gems for my gf. Her name is mimimoo. Problem is im using a android and she is using an iphone and im not used to handle an iphone. When i wanna buy gems on her account dragon era ask me for the way i want to pay. Im using a mastercard so i select mastercard fill in everything and then it says: the way u wanna pay doesnt work. But im using the same details for my account bershi. And it works. Do u know what could be the problem?
sry for my english im german

[admin]

Hi mimimoo, We don't actually process your payments, the app stores that you downloaded the game from does that. I haven't heard of this before, but you might want to first double check the parental control to make sure nothing is blocked. After that, you probably want to use Google (or your favorite search engine) to search the exact error message you are seeing in your native language which usually will give a good explanation what's going on within the first page of result or so. If you didn't find an answer, you can contact Apple's iTunes customer support who can assist you with the purchase issue.