FNB does not deliver what they promise!

I am appalled with the treatment i have received from a bank that i have been with for almost more than 5 years!!!! I accidentally subscribed to a google play app, called myheritage, not knowing that it will debit R1700 off my account! I phoned and emailed FNB debit dispute department and they sent me the necessary document. However, the response after that was that i should submit an agreement between the subscriber and i in order for them to dispute the amount. There is no such agreement!!!! I did not even use this ****** service. I informed them that i was just browsing and it was human error.I have not heard from FNB since......... This is ridiculous! I need that money especially in the times we live in today. Please resolve this and pay back my money. this is totally unacceptable.