Virgin Media - Leave and rejoin

Wrongislander

Myself and my partner have recently moved in with my mother and I looked over her bills. 
What I discovered shocked me. I thought, as agreed that she was paying the £56 all in that I had agreed at the start of the contract. 
What she's actually paying is between £70-80. She's still on the same old "mix TV" package, she doesn't have a Tivo Box, her internet is 24mb if she's lucky and she still has the same Full phone package (other than without mobile for 1 hour calls) 
I phoned up to query this and they basically said for what she's paying they will up the BB to 200mb, give her over 120 extra channels and a V6 tv box and add the free mobile for an hour calls. 
What this told me is that she's been missing out for months if not years and I wondered if anyone could help me answering the following questions: 
1) Do I have ground for complaint? I've checked her emails and there was nothing that told her she was entitled to a v6 box despite the fact her bill clearly says she's paying for a tivo box privilege. 
2) If we cancel her contract, can we immediately sign up in our name as we were not the account holders? Would we be able to keep the phone number from the house and if we did what would be the delay/waiting time between our new service being activated when her old one is cancelled. 
Any help greatly appreciated. 
Thank you and stay safe. 

JJ_Egan

Out of contract leave yes . Not out of contract pay remaining months off .