Mtn iesh

I tried to purchase an mtn modem from Mtn, on 16 June 2024. After numerous calls to call center no joy in getting modem and service by end July 2024 Went to MTN Tygervalley returned the modem and was debited R430 x 70 R31 000 and tried to stop the account no joy. Returned the debits but this month they still debit my account. Iesh how do we get this sorted?