VM send out a letter/email one month before price increase so 1st Oct this time. They know how to play the game, so you really have to be sure what the competition are offering. I don't think they do the ring back after you told them you want to quit any more. Ask for the last day of your billing cycle and payment date if you want the best deal. VM aren't interested in your business these days, just choose the best deal you can find.
Link;
http://www.moneysavingexpert.com/uti...-customer-tips
Remain calm and try not to insult, it's a game to VM, it's your money.