PAYG price increases on paid-in-advance charges and the UTCCR's

Garuda_2

I have a Vodafone PAYG phone & I top up £100 yearly, but recently the tariff has increased substantially and I have a lot of unused airtime, and that increase was obligated on me after I purchased that airtime.

I purchased the time on the basis of spending it at the pre-increase tariff and (it appears) I cannot transfer my unused pre-paid time to another supplier namely Virgin PAYG.

This appears to contradict the Unfair Terms in Consumer Contracts Regulations in particular Regulation 5(5) – because Vodafone had increased the charges for services paid to them in advance without giving notice of that increase and without giving the consumer an opportunity to exit the contract.

Help!