Planet Fitness incompetence

I joined the gym in September 2020 , hoping to get that free week. However, I was sold a 24 month contract at a rate of R399.00 pm, during their R199.00 promotion. The amount deducted though is R599.00. I have been calling the contact centre every month to follow up on the query and eventually it was changed - or so I thought, on the 25th of December they had 3 debit orders going through with the incorrect amounts. I also have a serious question on the credit, why won't they give me the cash back that they take *******ly?