Cellc to lazy to work

Been fighting with cellc now for weeks. They say my account is in arrears, which it's not. They say I didn't pay in April. Not one SMS, call or anything to notify me. 5 MONTHS later they switch off my line without any warning of any kind. After 3 months of no word from cellc you would assume payment was received. When I asked what amount I have to pay, they gave me an amount and I paid it on the 7th of Sept. No arrears was mentioned AGAIN, yet they keep saying I'm in arrears. Poor poor service. Cell c is still on level 5 lockdown apparently