Paid money cant be found

Hi! I have been paying my Game acc to Rcs Game via my banking app since last year June on a weekly basis: R100/pweek! I have sent them proof of this as bank statements! They dont seem to find this money since September last year! So they keep on foning me to say that i am in arears! Arear amount is R900, but i paid more then this via the app! Please assist?