Orange 2-year contract

Hi,

I have a contract with Orange which I took out in November last year. It stated that I could change my tariff as early as six months into my contract.

I phoned Orange a month ago and they said they'd make the change. I then found out today, upon receiving my bill, that they didn't make the change. They then told me today that it's impossible on their system to lower anyone's tariff until 12 months into a contract.

However, I phoned up later to speak to non-business support and they said that the terms were changed from six months to twelve months only in April. Because my contract was signed in November last year, they are legally unable to enforce this 12-month clause on me, despite what they say.

Has anyone else had this problem?