Just been on the phone with Customer Services. Chose the option for callback and half hour later got a callback. The lady on the other end said I needed to be transferred to the mythical 'Cancellations Department' at which my BS alarm went into overdrive. Got transferred through to an automated system with no option for callback. Half hour wait and have given up. Now expecting to jump through a few rings of fire to cancel a monthly service that you should patently be able to do on Self Service. What a swiz!
If you wish to keep the number, you can contact the provider you want to go to and ask to port over. That way you don't have to be put on hold to wait. If you just want to cancel it and that's it then unfortunately you wil have to wait. Best to try at 9am when call times are shortest.