I got several calls from retentions during my notice period that's just coming to an end, so its very likely they'll call you, and with a bit of persistence they will offer you new customer packages or near enough. There is of course no guarantee they'll make those calls and you'll be around to receive them, so if you're cancelling only as a tactic, you might want to prioritise getting to the phone if it rings.
An important point for everybody negotiating deals with VM at the moment is that unless agreed otherwise, VM deals are fixed discount against the standard price, meaning that VM will honour the discount for the fixed term, but can increase the underlying contract price at any time by any amount. It's widely expected VM will bring in an inflation busting price rise this year in the region of 11-14%. If a deal has a standard rate of say £50 a month that you negotiate down to £34, then the 12% rise would apply to the full rate, and be a £6 a month increase. When that £6 increase is applied the contract £34 a month, that's a 17.6% increase you'll see. So either factor that into your calculations or try to insist on a fixed price contract. Be prepared for the possibility that they won't offer a fixed price deal, and think about your options then. If the price increase is "only" around the 10% of CPI, then I think that Ofcom's interpretation of their own rules mean that customers can't cancel or renegotiate, if it's above CPI I think that they will be able to, but as other competitors are eyeing up similar increases, market prices may not be as attractive in a few months time as they are now.
In my case I told the retentions people "No thanks" since I've got a fixed price contract with a smaller competitor who have a reputation for great service. Supplier I chose was Aquiss via a new Openreach FTTP line, if you're interested. The key thing to note about Aquiss is you provide your own router or mesh system - I like that, its not for everybody. VM might well have beaten the Aquiss offer if I'd tried, but there's real value to me knowing that my price is fixed for 12 months, and unless VM mess up my cancellation that call was the last time I'll ever have to deal with VM.
