O2 500mb data cut - Cancel Contract? (non iPhone)

gunark

Hi,

I signed up for a 24 month contract on O2 mid may, £25pm. I also agreed to pay the £5 for the unlimited web bolt-on but as I had an O2 Open code they added it for free (or at least they said it was free due to the Open code). Was pleased with that as I specified prior to this I wanted data of 1GB or more and the assistant said he thought it was 1GB to 3GB he thought. So now I have been told that my tariff will be cut to 500mb which has gone against why I even switched to O2 in the first place (incidentally it was because with Virgin I exceeded the 1GB by 90mb and they charged me £81, so I switched to a better allowance). I realise iPhone people seem to have no get out on this but as mine is not and iPhone tariff and the contract states:

"If
 we
 increase 
the 
Charges
 to 
your 
material
 disadvantage 
or 
we
substantially
 vary
 these
 terms
 to 
your 
material 
disadvantage
"

So as they have taken away the reason I signed up in the first place, can I cancel?

Incidentally, I have asked 4 different O2 assistants, both in store and by phone, to tell me what my limit is and I have been told from 200mb to 1gb to 3gb to "dunno, unlimited I guess". It's pretty staggering no one can actually tell me!