The price rise is from April. You should have been notified in advance. I knew about it but not sure if I got any notification or if I just saw it mentioned in forums - I've checked my VM email account and don't see anything there, nor do I remember any postal notification. As it's only £1.50 and I'll be ditching VM as soon as Infinity launches here (June I hope) I wasn't fussed.
The upcoming speed increase has been in TV ads and on internet adverts for some time and I had several emails about it. Very few areas have seen the network upgrades yet but unless your area is oversubscribed you can request a speed increase but it will extend the contract and will only effect downstream not upstream.
Same for me regarding infinity. I signed up at £28.50 for 30mb they have since put up the price to £30 even though its advertised at £27.50. It seems that like all businesses they don't reward loyalty but would rather push for new customers. In the typical British manner I don't complain directly but will take my business elsewhere as soon as the opportunity arises.
If you've been with VM for any length of time surely you already knew that they set their prices as if they were running a car boot stall. There are no automatic reductions when the new customer price falls you have to call in to get them to match it which they will do but usually that will trigger a new minimum contract term unless you can get it agreed without that. That's what comes of dealing with a bunch of shysters.