on 25-07-2012 20:01
Two best options are.
1. If you don't want to keep your number - ring up to cancel 30 days before the end of the contract
2. If you do want to keep your number - ring up and request a PAC code which you give to your new supplier. Once transferred, you old contract will come to an end
You must port your number within 30 days of receiving the code
If you don't port your existing contract will continue