Cancellation depression

Ive joined Virgin active last year in August and I would like to freeze my account because im going to Mozambique for an indefinite period for personal reason but because im a vitality member I cannot do so im forced to cancel its no use in paying for a membership if im not going to use it for a couple of months, when I spoke to the lady at the call centre she did explain that there will be a cancellation fee and I do agree with that as I did go through my documents that ive signed, and then she said they will be deducting a normal monthly fee for feb as well, afterward ive been thinking that that is very unfair and why should I pay for Feb if they know im not going to use it? if they can put a debit order through before feb for cancellation fee they can surely stop the monthly fee with emmediate effect.,...why do I have to pay (in advance) for a month we all know im not going to use?