Incorrect membership fee was debited

I wanted to cancel my membership after many years being with Virgin active. Which I proceeded to do so beginning of the year 2024. Before my membership came to an end I got called by one of their staff Wafieka Williams on the 24th of Jan, she offered me a discount for 4 months in order to retain me as a client, so from what I was paying which is R197.50 I would be now paying R98,75 over that period . She sent email confirmation of what we discussed. To my surprise on my following debit order I got debited R395 more than what I’ve ever paid. You can imagine my frustration after trying to cancel and then being debited more. This is the worst experience I’ve ever had with Virgin Active by far. Please can I get this resolved asap