First bill after renewal

I’ve had an absolute nightmare of late. My contract was coming to an end, Virgin contacted me and I ended up accepting a renewal with an upgrade to Virgin 360 plus at long last an upgrade on my hub from the 3 to the 5. So it was supposedly a self install which would take me 15 minutes. What a joke that was - received the kit on the Tuesday engineer had to visit on the Wednesday, Thursday AND Friday - bless him he’d never had such bother and I had 3 days of being inconvenienced and now everything is up and running I’ve had an email saying my next bill is for the ridiculous amount of £186 when it should be £131 (new contract is £120) - I’ve tried phoning but the automated stuff is so infuriating I end up hanging up, I’ve tried chat and they were of no help at all, asked Shiny to have someone call me - I can’t do that as I am the web chat team. Honestly driving me mad!