Worst Service From Telkom. Telkom please reach out to me, I want to cancel my agreement with you

Very disappointed in Telkom's services.

Please advise how can you suspend/ deactivate my wifi Sim prepaid account and still charge me a monthly installment every month. I am no longer interested in continuing my contract with them and have been trying to reach out for almost 4months now, with no success.. Yet they send demanding messages about outstanding fees.