cancelation of a contract is a nightmare

Alert when taking a contract from MTN, please note that will be a two year sentence, as they will impose a high cancellation fee, for sim only contract imagine what they will do if is a cell phone contract, I am not getting value for money, network is an issue and yet to cancel they need 900+, had the same contract with cell C, when i cancelled they only asked why, and the contract was cancelled hassle free, please when taking a contract ask MTN on record if you are not happy with their product how much are they going to charge you