Poor service

I lost my sim card for my contract tab and called the call centre to get a replacement sim and was turned down stating I did not use the sim for over3 months and they cannot give me a replacement sim and I need to go to a store to get a replacement sim,take note I was not using the sim but still paid the monthly cost for it,came a point when I went to the store to request a replacement sim and was told it was not possible as the sim was not used over 5 months,called CellC customer service about this and came to a point of cancelling when account was upto date,was transferred to the cancellations team and call was dropped on me 3 times and I really was tired and frustrated about the situation and asked just to have the account cancelled, agent said okay it is 30 days notice and ended the call on me and ever since I did not receive any confirmation about the account being cancelled as I requested,in the month of March I was sent an sms on my alternative number stating my account is in arrears for the months I cancelled the direct debit,in all honesty I feel this is very unfair on my side as I was a slow payer but never in arrears on that account,dissapointed with the customer experience of CellC