Can I cancel my newly entered into SIMO contract?

[Anonymous]

Hello,

I 'upgraded' 1 month early to a 12 month sim only contract on 30th October (5 days ago) - the £20 On & On contract.

I have now changed my mind and would like to cancel my contract an go to another operator with 4G capabilty.

What cooling off period do i have? I 'upgraded' online.

Thanks all.

[Liquid]

**bleep** I'm jealous now:(