Worst ISP ever DO NOT USE THEM

I have been paying for a 4mbs line for the past 4 months and not once have I received 4mbs line quality. at best I get round 1.6mbs line quality. I have logged multiple complaints over the phone and online and this has never been resolved. I have been over charged, more than what was agreed up on, and when I asked for a reduction in payment due to bad service got only R200 deducted off a R2500 bill that is already R1800 more than the contract states. And still nothing has happened.