Complaint against nimble group

My name is Anelisa Mvoko, I had a gym contract with zone fitness that was handed over to nimble group. I made an arrangement with nimble group that they can deduct R250 a month of which they did. Every month they would forward me a statement, as per usual on 10th July 2024 I received my last statement stating total due is R141.75 which will be deducted on the 31st July 2024 and then I would be done with that account and to my surprise on 31st July 2024 they deducted R250. When I called nimble group customer care the agent informed me that it could be that the system was not updated for R141.75 deduction hence an amount of R250 was deducted of which that is failer on their side and not my fault. I even went as far as sending an email on 31st July 2024 to be reimbursed the difference, but up to now they have not done that. I called again on 6 August and i was informed that they will attend to.the matter. I sent a follow up email on 14th of August 2024 the only thing they rep**** by saying they experiencing high email volume and they will respond immediately of which that is the same reply they sent me on 31st July 2024. Since 2 weeks I have not received any valid response for reimbursed of the difference. Could you kindly assist in this matter.