Indeed it should, but that was my point. Your course of action is rather determined by what end result you want. One option is the speed you paid for. Another is a good
compensating discount until you do. A third option is to be formally moved to a lower speed commensurate with what they can provide. A fourth, if you think you can do better elsewhere, is to be released from the contract.
In ANY of those scenarios, unless they agree to what you want voluntarily, your best bet is to start documenting everything. Detailed notes of phone conversations (date, time, number dialed, identity of person answering, notes on what was discussed/agreed), etc. Better yet, record it. Don't publish the recordings, but for your own records .....
And even better, start doing it in writing, preferably recorded delivery. There will be a complaint process. Follow it. If you are getting jerked about by customer service, ask for a supervisor (good luck with that, by the way, but
record that you asked, and what happened).
Ultimately, you're in one of three situations :-
1) They concede, and give you a satisfactory solution, or
2) You give in and give up, or
3) It comes to a fight, and maybe a court case over breach of contract.
Hopefully, you get 1). In which case, problem resolved. Or, you decide it's too much hassle and go for 2), in which case, problem still over.
But if you end up with 3), it is
overwhelmingly in your interest to be able to
prove two things - first, that you have been reasonable, and patient, and tried to resolve it, and second, that you have carefully documented every step of the way.
There's one more wrinkle.
I can't say about VM, but I have come across companies in the past where a large part of the function of customer service is to deflect customer complaints, and make them go away. And they are often very much aware that many people will blow off steam on the phone, but never get around to actually doing anything concrete beyond that.
There is no universal solution, but my methodology involves trying to resolve things on the phone, but if that doesn't work, I confirm in writing. That does two things - it gives you a formal evidence trail, and it sends a psychological message, you are aren't just giving up. Also, you're following a path they will recognise. My experience is that that is often enough .... assuming I have a good case/argument, of course. If that gets nowhere, my next step is to put cc. <my solicitor's name> on subsequent letters, which is another hint to the path I'm on, and a none-too-subtle one. If that still doesn't do it, a letter from my solicitor
so far always has. Of course, that last step costs, and I DO NOT do that for bluster. If I go that far, it's because my solicitor reckons I have a good case, worth pursuing. But that letter, because it costs, sends them an unequivocal message that you aren't just giving up, and costs for them are about to start piling up. So if CS were just blowing you off, that'll stop. At which point, either they give in and you get 1), or you have the written supporting evidence you need for 3).
In any event, you do have the option to allege beach of contract on their part, but if you do, you want to have done everything reasonable to resolve it first, because winning a legal fight may depend on having done so, and that includes following their complaint/dispute procedure.