Dysfunctional processes and/or *********** staff?

On 25 February I called Vodacom to upgrade my account without a new phone. I accepted the upgrade offer. 30-day notice for change in contract to run during March. New monthly contract rate payable from end of March. Great.

Vodacom sent an unsolicited sim card with the upgrade to an outdated address (I was at no time during the upgrade offer informed that I should receive a new sim card. The simcard was sent erroneously.

I phoned on 9 March to enquire about why a simcard was sent to an outdated address and was told that the upgrade was cancelled because the simcard was returned to them. I was assured that the upgrade would be re-instated on the 9th of March.

On 26 March I received an SMS notifying me of a debit order due to be deducted from my account that still had the old contract rate on. This is more than a thousand rand extra to be deducted from my account. I phoned Vodacom to resolve this and was told by Nonhlanhla that the upgrade would be re-instated (again) and that while it may be late to change the debit order, that the money would be paid back into my account as soon as it was deducted.

I gave the repayment a few days to occur, but nothing has happened in 3 business days despite being told that it would be paid back immediately. When I checked on the MyVodacom app yesterday, I noticed that my contract information still indicates the old contract, which means that my call on 26 March has also not succeeded in re-instating the upgrade.

VODACOM - how do I engage with you to get the outcome of re-instating the upgrade agreed upon on the 25th of February and also get paid back the additional money you withdrew from my bank account due to no fault of mine, but due to your errors and inability to respond to my multiple calls?

Please help, I'm searching for a constructive solution.