VM normally refuse to let customers leave without paying the big fat early termination charges, although in cases of over-utilisation and/or clear evidence of problems sometimes they'll quietly agree to release without penalty.
If you can make a good, evidence based case of repeated problems (eg BQMs showing similar poor performance over some months) then you could run it through a formal complaint, see what happens. If you get a fob-off resolution, reject the resolution and ask for a deadlock letter, and then escalate the matter to CISAS. Unless you've already got an unresolved complaint with VM that you could escalate, it would probably be six weeks to get it to CISAS. In either case, perhaps another month before they come back with an adjudication, and if in your favour you'd probably still have to give 30 days notice. So it isn't quick if VM choose to fight, depending on circumstances you might choose not to bother, and to review the situation when your fixed term ends.
If you're heading to CISAS, remember that the poor adjudicator knows nothing about your problem, may not be a gamer or techy-savvy. Explain the problem as it affects you carefully, and avoid diagnosing faults with VM's network. Although you and I may have a view on it being over-utilisation, we can't prove that unless VM have admitted it, what you should have evidence of is BQM's showing persistently poor latency at peak times, or showing unreliability, plus anecdotal experience of how this affects any reasonable uses of the connection, and some explanation of how you've tried to get VM to fix it, and the outcomes from that, along with your customer experience in trying to get them to resolve things - say as well how all this makes you feel. I think the relevant "about the problem field" on the CISAS website appears limited to about 1,900 characters including spaces, may be worth typing this out before you start any complaint. Make it easy for the adjudicator to understand the complaint and what you want out of it.
