Complaint for Telkom

I am very angry and unhappy with the service we received from Telkom. My mother purchased a Home Wifi from Telkom that is on promotion for 12 months. We were then informed that we have to pay R700.00 deposit, the monthly payment for the wifi is R215.00 so we were told that because we paid the deposit amount upfront, we won't have to pay the monthly payments for 3months for it will be deducted from the deposited amount, that was what we agreed on. On the 15th of November 2023 the company debited the R215.00 from my mother's account and the agreed 3months pay-free period had not ended, we were also sent the invoice. First of all, my mother works very hard for her money to be deducted without clear understanding. We went to the store to find out where did we miss understanding and our matter was sent to Telkom Billing. They later contacted my mother claiming the deposited amount is to secure the account and if ever we miss payment they will deduct from there. We want the debited money reversed back into the account if not we're taking the matter elsewhere