mobile phone contract issues

got the samsung galaxy s2 and it won't wotk on 3g. told vodafone and the woman who wrote the email says to change the settings to 2g!. surely can't be right as i'm not getting the service offered by the phone.
secondly i continued a contract i have had for about 6 years now, 900 mins unlimited txts and unlimited internet.
got a txt from vodafone saying i had exceeded 500mb limit and they were charging me £5 for another 500mb.
i'm not bothered about the money, but surely i should still get unlimited internet as i'm still on the same contract.
am i right or wrong, as i've emailed them back saying they are in breach of contract and that i want it cancelled.

 

There will be a fair usage policy for unlimited internet so really unlimited is a little bit misleading but all the networks do this. Check in your terms and conditions

 

Er you are paying for internet use you can't get on your phone?

 

You'll have been notified as to the change in your T&C (500mb Internet usage) in an email or with a statement. It's normally taken that if you agree with the new T&C you don't need to do anything. If you didn't agree then you have 30 days from the notification to cancel the contract.

Or they may have slipped in the fair usage change on your contract anniversary, your contract normally runs for 12 month periods.