Rokk Strongo

I am playing pathfinder on a samsung tablet and am logging in with my google play account. But anytime I try to buy gold, the payment window shows up with the google play account of my gf (who is also using the tablet from time to time). There is now way to change the account dure the payment. Also, although I am logged in, google play wants an other account to pay. Could you please help me to buy your stuff? Thank you