Morning I have been ...

Morning I have been harassed by MNet for the past few months They are trying to force sell me a new decoder, implying that they can cause the existing decoder to crash We bought our initial decoder on our own without mnet and will do the same when we need to replace However they want to sell us one forcing us into a contract at R200 for 24 months We pay our monthly subscription via internet and not debit order which they also have been trying constantly to have us change How do we stop them harassing us