Worst company ever

Very useless company, been having a unit for 2 years with them never missed a payment, when I tested my unit a month back I was told it is taking long to bring the location and I will be phoned back which did nit happen. Today I phoned them and asked to cancel my contract as I cannot be paying for a unit that takes longer to give location all the time and I was told I need to back +- R1000 for cancelling a unit that is not working. My unit is not working and I must pay R100p for it to be fixed