VODACOM FIBRE ****!!! NOT WHAT I SIGNED UP FOR!!!!!

I signed up a few month ago for Fibre 20mbs line, Vodacom then installed the incorrect line (4mbs) SAME AS WHAT I HAD AT THE TIME!! When I phoned to query this, they told me that I completed the application form asking for a 4mbs line!!!! Why on earth would I sign up for something exactly the same than what I have and pay DOUBLE THE PRICE CAUSE IT FIBRE!! They then appologized and said they would send someone to correct the fault, 2 months down the line, I am still waiting for someone to "upgrade me", I then asked them to cancel the line all together and come and remove their modem and equipment that I dont want!!! They have NOT contacted me at all!!! I received a SMS from MBD Attorneys today saying please pay R1989 today on your VODACOM ACCOUNT TO AVOID BEING BLACKLISTED!!!! WHAT THE HELL?????? DO NOT SIGN UP WITH VODACOM, ITS A **** AND THE SERVICE IS PATHETIC, NO UPDATES, NO CALLS, NO CANCELLATION REQUEST, NOTHING!!!! BUT THEY WANT THE MONEY!!!! WHICH I REFUSE TO PAY!!!! I WANT THIS BILL CREDITED AND YOUR EQUIPMENT REMOVED VODACOM!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!