Mondo MTN pathetic service and cellphone cancellation charge

I received the worst service in my years of ordering cellphones from MTN. I ordered an Iphone 13Pro in October 2021, i never received the phone and was told by Mondo that my request was cancelled in February 2022 after i had waited for months being told there is no stock.

After that on the 15th of February ordered a Samsung S21Fe which was advertised with a Samsung tablet, the phone only arrived on the 15th of March, when i asked about the tablet, i was told i must claim it from Samsung.

When i went to Samsung website it said the claiming of tablets had ended on the 28th of February. I called Mondo and MTN and told them the deal was for a phone with a tablet, if there is no tablet i don't want the cellphone. They said i must cancel the contract.

I cancelled the contract within the 10 day window period of receiving the phone without using it. Now they have sent me a R17000 cancellation charge. What kind of service is this?