FNB de*****ing me on FNB Connect

FNB is de*****ing clients with vexing customer interface on FNB connect. I was on a contract for 1 month. Wrote emails to the consultant who arranged for the FNB connect to cancel or downgrade to prepaid to allow for porting to Telkom. Made calls, visited the branches 2 times and assured that it is prepaid. Yesterday they debited me for 20Gb top up. I spent R100 on the phone talking to the call center. Still no case number. No resolution. I am supposed to pat rent but I am now short of R700 just because FNB wants to profit. I have used all channels to get out of this, but FNB just doesn't want to stop. Best thing is to close the account because the abuse is raw. You can't even get a case number