Seven months to close an account and still no refund of monies deducted!

I am extremely disappointed with the service I've received from Vodacom, although I've been a customer of theirs for many years.

I emailed Vodacom on 7 September 2020 to cancel the two data contracts I had with them (one being a mobile wifi device sim and the other a data package for my Tablet. They managed to cancel the mobile wifi device contract and no further deductions were taken from my bank account. The Tablet sim was a whole different story. I have called them SEVEN times (the first time being 25 August last year) and the 7th time being 23 March 2021. Each time I called I was told that the contract will be cancelled and that no further deductions would be made, however for 7 months an amount has been deducted. Every person in the contact centre that I've spoken to (I've made a note of the dates I called and to whom I spoke) assured me that it has been escalated and will be rectified, but alas, the following month arrives and once again there is a deduction from my account!! FINALLY the last invoice/statement I received (dated 31-03-2021) it shows that I have a nil balance, and yet a deduction was made on 01 April!

I have spoken to Denzel, Selby, KG, Phulani and Nonthantla at Vodacom customer care and all of them have told me the same thing - this has been escalated and that I will be refunded for the seven months of deductions. Even though my balance now shows as zero, there has been zero communication about the refund for the amounts deducted. When I called *** this morning, the automated voice told me "sorry we can't help you as you are a pre-paid customer" and to call a different number (082 135) with another automated voice saying that I need to call from the number that the account pertains to (which is a data sim!)

I would like someone (other than a contact centre agent) to resolve this and the refund credited to my account as soon as possible. Can it really take SEVEN months to get a cancellation right?