Am having a problem to subscribe an app

I don’t know what happen to my Talkatone app if I want to pay into it Talkatone and it we show me Purchase Error or it we show me that subsciption owned by an other user how can you help me out please

I don’t know what happen to my Talkatone app if I want to pay into it Talkatone and it we show me Purchase Error or it we show me that subsciption owned by an other user