Yes the upgrade is made by phone. When I first called Phones4u it was just 2 days after the receipt of the handset. At first, I said that I would like to swap the handset and was told to wait them call me back within 7days, and then I said I would like to cancel the upgrade. The advisor did not say that I have no right to cancel but said that I need to ring another department. It has now passed 7 days and I am not sure if I can still ask for a swap, although they gave me a ref. number to prove that I had requested a swap within 7 days.

Thanks a lot Buzby, your reply does really help. I am a foreigner here and know little about the mobile service. As you said, I used to simply terminate the old contract and begin a new contract before, but this time I tried to upgrade it, not a good try I would say. And yes I agree that PAYG is a good option without too many troubles.

Well, although I still do not understand why a upgraded contract can not be cancelled, it seems that I will have only one choice to swap my handset. The problem is that my old contract is with 3G and so is the new one. Can I ask Phones4u to change to another network such as T-mobile?

Thanks for your reply. Just wondering if I can just bring it to a local store for cancellation or for a exchange? Really not willing to call them, always busy, takes me over 20min each time.

The phones4u shop just sent me a mobile handset for upgrade. But I don't like the handset and am going to post it back, as the sales told that within 7 days I can return it. Today I called the customer service and I was told to wait them call me back since they are always busy. And they will call me within next 7 days!! Now I am just wondering if I can just post it back and cancel the upgrade with 3G? Thanks for your help.