Utterly poor service

Utterly poor service, I am paying for a 10mbps line, and i am receiving 0.8mbps. i am paying for a service i cannot use. is this fair i think not. when i asked for them to cancel my contract they said no i must pay R1000 cancellation fee , is this fair.....i think not . Why should i pay to cancel my contract when they are not providing an acceptable service? As a customer i am left furious.... next step lawyers