Were you correctly informed of your contractual requirements before signing up?
Quote from COMREG document 'Comreg 03/129', available from their website.
In respect of new end-users, the normal law in relation to contracts apply, i.e. in order for terms and conditions to be valid they must be brought to the attention of the end-users before any agreement is concluded. This may be done, by giving a written contract to the person or by drawing their attention to where the written terms and condition can be found. These standard terms and conditions should be published in a manner which is sufficiently transparent and easily accessible to end users and a paper copy should be provided to any customer who requests it.
End Quote - (emphasis added)
So did you receive a written contract as you signed up? Or were you given an exact URL of where the contract could be found on the website, i.e ww.vodafone-xxx.com/Contracts/Contract123 ?
My belief is that Vodafone neither provide a paper copy of the contract, nor do they tell you where it can be obtained...
Incidentally if Vodafone claim that you were referred to their 'website' I'd argue that that is insufficient to allow you to download the correct contract.. exact URLs are required.
Cheers so,