Telkom mobile

Hello i have a problem with Telkom mobile, i took out a contract phone with Telkom last year so what happened is that on March 2020 Telkom mobile over debited me and as soon as i realized that i went to 1 of their branches to complain about that and they give me their financial department contact details. I called them and they acknowledged that it their mistake and they promised me that they will refund me my money within 7/14 working days, bare in mind that this was in March 2020 and i understand that we are on lockdown now due to Covid19. On 25 April 2020 Telkom mobile was supposed to debit R199 on my account for their mobile phone but they didn't do that and i told myself that they are just going to deduct that amount from the money that they owe me because i haven't heard from them and it's been a mission to get hold of them and yesterday i got a message saying that my mobile account is overdue and i should make a payment of R656. 59 to avoid suspension or cancelation of my service. I still haven't received my money from Telkom mobile but I'm getting a message that i should pay them while they still owe me money and they acknowledged that it's their mistake. I'm not getting any help from Telkom branches and i can't get hold of the financial department of Telkom