Impossible to cancel contract - no communication from MTN

Tried calling retentions numerous times to cancel my and my wife's cell phone contracts early. Each time I sit on the phone for over an hour before giving up. I cannot sit on the phone for so long - I need to work for a living. My wife and I then emailed retentions on 14/04/2021 to serve notice on our contracts. Reference numbers: *** and ***. It is clearly stated in our contractual agreements that we can give 20 business days' notice in writing. We also requested a pre-cancellation quotation to settle our accounts. It has been a week and I have received no communications back. Pathetic. How can it be so difficult to cancel a contract?

As stated, I have tried calling, but I don't have time to keep trying this avenue. We are emigrating and are trying to do the right thing. Once our notice period is up, we will cancel our debit orders. Please contact me to arrange for the settlement.