Undo membership cancellation

Hi,

I have just made a mistake and cancelled my membership plan and I still had loads of months to get through as I had the annual subscription. I would really like to undo this cancellation but I'm not sure how. I also really don't want to wait out the membership cancellation and to be charged the cancellation fee which I can't afford and then get a new membership afterwards.

So is there anyway to undo my cancellation?

Thanks,

James