The olden days are gone of new customer pricing deals or better at the moment. VM don't HAVE to give you any discount so you do not have entitlement, even if past experience you have got discounts for recontracting. If you cancel now, you **may** get a call back. In my case it was SMS the day before disconnection. Too late to do anything and the number had a robotic answerphone on it. Customer Service on phone clueless as usual *and expected* and didn't know how to apply the offer. Before people go in with cancel requests, be sure you may have to actually walk the walk too. Know your competitor pricing (like NOWTV monthly FTTC or ADSL Broadband or 4G/5G SIM only, contract free) and whether you could cope on that for 90 days before re-joining in the original account holder's name again as a new customer.
Ensure you book a new provider as soon as possible after cancelling, as it gives time for any problems to be sorted before VM disconnection. After 90 days of disconnection, you can come back as a new customer with all the usual free gifts, topcashback/quidco and potentially newer models of kit than previously, and new customer pricing, or you can switch to a partner at the same address as discussed lots of times on the forums without waiting 90 days.
Forum staff don't do package deal negotiations either.