fibrestream - i want out of your contract -

I am disappointed with the service i am receiving from fibre stream. We have a contract with them for 24 months and now 8 months into the contract we are always having poor or bad connectivity to e precise- we can be out of a network for a week and more and still pay R899 pm - when trying to get out of a contract we are told to pay a penalty fee of R12 999.00. i feel this is day light ******* since the company is not delivering as per the agreement!