Cancellation request not processed

I made an online purchase of the Samsung A23 handset 2 for 1 deal last month, the cell number allocated is ***. On the 21st June they delivered but only one device was brought and when I called customer service they said one device was cancelled due to stock. I advised I was no longer interested and the consultant advised me to return the device to my nearest MTN store and get a reference number which I did on 25 June at Liberty Midlands Mall.The reference number is IRMS852941. I called Mondo customer care on Monday 27 June to give in the reference as I was advised to do. I am extremely disappointed as the first consultant put me on hold then hung up and then the next consultant Anisha repeated everything more than once and then proceeded to put me on hold again and after 15mins my call cut due to me running out of airtime as I called from my cellphone as they said they could not hear me on the landline. I went on the Mondo "Moebot" contact centre and I received an email on the 2 July saying the cancellation was in progress and I would receive feedback within 2 -9 business days. It's been longer than that with no feedback. On Friday I received my MTN statement and reflected on there for the Samsung A23 was an amount of R368.26! My MTN account for this month is more than R1200 as Mondo did not do their job properly.This morning 18 July 2022 I have tried 4 times to call and the consultants act like they can't hear me. This is so disappointing and frustrating as we as consumers are already having to pay high prices for food and fuel now to be cheated out of hard earned money by ********** companies like Mondo is extremely disheartening. Can the cancellation to this account please be processed IMMEDIATELY.