If you want to move to another network then you just do it and ask them to port your number over from 48 to their network.
There is no cancellation to be done at the 48 end - other than making sure to switch off automatic membership renewal if you have it enabled to avoid being charged automatically for further monthly memberships.
By the way there's no need to spam the board with multiple threads (merged into one here) and posts. Posting once about a particular issue is sufficient!
Hope this helps.