Gives Contracts without Consent

I had a Contract with Cell C a few years ago, and I completed the contract and sent a letter when it was completed to cancel the contract, in this years I get a lawyers call to informed that this contract has a bill attached, and that I must pay the bill. they never closed the contract, and I do not hold this letter any longer, as normal humans don't hold info like this for 5-6 years! <br> <br> Then today I get a sms saying your contract has been approved, dial this number.... Who gives them auth for a contract nor any paper work signed!<br> <br> then you try and call them and nobody knows where calls needs to go and you hold on the phone for 30 min + and still you don't get any help!<br>