Pooper the same has happened to me, I have escalated a complaint against them through ofcom.
My discount was given by VM, ntl was dead and buried only in the wording, in my own belief it is still ntl in vm clothes.
I got the same botched up letter about my telephone service, I am with BT, it was only when I questioned it that they said it was to do with my broadband.
I was given 12 months discount last year by vm, now they have decided to withdraw it claiming it was a mistake, first of all they claimed the discount should have only been for a month, which there is no way that I would have accepted that offer, then yesterday during a telephone call from vm about my complaint it was quoted that the offer was now a 6 month, not a one month or the 12 month offer I was promised last year, the person went out of their way to explain that if it had been a 12 month offer then that would have required a new 12 month contract, again that was not mentioned last year so I told the adviser yesterday that at no stage was a new contract mentioned.
I am now tempted to pay the £10 and get my file under the rights to access because they really are taking the proverbial.
All I can say is once you find out the true reason for the letter you either accept as a fact of life what they say or you can go outside of vm with a complaint, maybe if more people do go outside of vm then some questions will be asked as to how so many customers can be wrong in what they were told.
Good luck either way
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