********** Billing - WebAfrica

On 25th August 2019, I did an upgrade on an Internet account with WebAfrica. The upgrade process went smoothly and it was scheduled to be effective 01-September. Suddenly, on 01-September, I see there's an additional amount thats been added which looks to be an admin fee in excess of R300.00 I contact them and the billing dept will credit my account with this amount as its done in error. I advise I don't a credit, its not my fault and that they should invoice and debit the correct amount. I'm told its not their policy. I have to pay for their mistake? This is not my first bad experience with WebAfrica. I want my money refunded and not a credit passed on my account. Lots of back and forth getting no where so I now opted to cancel my services. Apparently I can't do that either. It HAS TO BE a calendar month's notice. They going to bill the amount(which includes that admin fee). This is an UNAUTHORISED transaction which constitutes *****! They messed up and the consumer has to pay. How many other customers has this has happened to?