Poorly trained staff

I've purchase a contract last year with Cell C. Received the device end of Sept 2021, cancel it 5days after. The call Centre agent j firms me to pay a cancelation fee and my 1st month installment, which I did. No one mentioned that I must give the device back, and Ive spoken to numerous people in that month, confirming its the right way to do the cancelation. End of October 2021 I've paid the amounts, emailed my proof of payment, and called in to secure my cancelation. The call center agent was happy and said yes it will be canceled.

End of November I only paid for one contract and I was happy. But all of a sudden a huge amount went off December and January. I've struggled to get hold of them. And when I eventually did, I was told they don't know why the amount is deducted. I called again and on my third attem3i got through to someone whom informed me that my contract has never been canceled.

Aparently they send the data allocated to the canceled Sim, every month. I asked why haven't the contract been canceled as instructed by me, and they couldn't answer.

Eventually somebody called and said if I don't return their device, then I owe them R9000 otherwise they won't cancel.

So why do they not properly train their staff. I spoke to so many regarding my cancelation and nobody asked for the device. Cell c is ***********. Poor servixe