Promised 1 yr contract. Told it would be 'changed in the back end' - now nobody will confirm.

Hi :) 

In January, I took out a broadband contract with VM. Initially, I was told I could have a one year contract on the chat function. When I was ready to take out the contract, I phoned (many times - service was shocking) and eventually spoke to someone helpful. 

To add context, I went through a bit of bath and forth, because the previous tenant on my flat was refusing to cancel virgin and saying she still lived there. Anyway - because I had evidence of being promised a 1 year contract by the chat function (screenshots) the man on the phone discussed with his manager to see what could be done. Later that evening he called me back and officered me the one year deal with agreed upon pricing etc. He told me that it would appear as 18 months, but that it would be changed in the back end and would absolutely end in one year. He promised to send over written proof of this. However it's never appeared. I have emailed the contact I had multiple times and I've been ignored. 

I'm concerned virgin will just say I've made this up... but I had multiple call backs etc discussing it. 

My contract should end at the end of January, but in the account management section it says July 2026. I'm obviously not going to pay another 6 months because someone has lied to get a sale... 

Maybe I've been naive, but I didn't think that Virgin Media customer service reps were allowed to outright lie to you in this way to sell, and that I'd be left paying for it. 

Has anyone else experienced this?