Telkom incredibly poor service

Poor service. cannot resolve a billings query. I took a contract in store at ballito junction mall in April 2023. The contact was for fixed fibre 25Mbps line at R579.00 per month for 12 months. The sales staff in store did not notifiy me of the price increase effective in may, the very next month. now im stuck with a contact that im paying R50 extra per month. the store cannot find my contact. and the sales or billings department cannot assist me to resolve the problem. I want to be billed as per the written contact signed. had i known the contact would be ammended without my consent a month later, I would have not taken it!!!. till date i have not received a single invoice from Telkom for my account either.