Overcharged for re-connection & Poor Service Delivery

Me and my partner has recently purchased a home with fibre line already installed. We confirm with sales agent David that the only fees payable is a reconnection fee of R995.00 on which he gave us an R500 discount. Amount only now due according to us is R495.00 for reconnection. After line was activated two weeks after our application which normally takes 3-5 working days we are being billed for a new installation service fee of R2720.00. Communication and service delivery has been nothing but poor even taken the pandemic into account. We receive an email relating to an credit of R1750.00 but here we are days later and our account has not been updated.