Overcharge/ Misleading customer with their products.

One of their call centre agents called me in December last year and sold their fibre products, he told me they have a promotion of R449 that I'll start paying from end of Jan 2025 for 3 months then after my actual monthly payment will be R550. We had a contract agreement to debit the amount on the 7th of every month from end of January 2025. To my surprise R993 was debited on my account yesterday which was the 8th. I'm not happy with their service and I feel the company is ****ming and reaping people their money. When I called them I was told that I was charged December and January and the fibre was activated on the mid month of December. I'm not happy with their service and I wouldn't advise anyone to use their products.