When you call them, they always ask you to turn off your router. I even said to the last advisor is it bad to keep on restarting the router or turning it off and on. He said you can restart the router when the speed drops low (<8MB for BT Infinity 1) but don't turn it off and on but I now know this is just as bad. I asked him if an engineer recommended a new router would I have to pay for it as it's older than 12 months. He said maybe, maybe not! I then said the stats from my cabinet show that it's between 29 to 46MB (last recorded May 2017) and asked how can that be correct when you've told me my minimum guaranteed speed is 43 MB. I asked why couldn't BT check if it was a problem at the cabinet first before visiting my property but he just said that's not how they do things. Apparently Infinity 1 speeds are currently being boosted, if possible, up until mid November 2017. However, I know I'll never get the stable 42 MBs speed again which I was getting a few months ago. He recommended an engineer because that's all they ever do now. I know I haven't changed anything in my home since the speed was good and stable but still think that I would be blamed for the fault and still do not know if I would have to pay for a new router if it needed one. £130 is far too much even if it was one's fault. Rubbish customer service. I'm definitely moving when my current contract ends in a few months.
I'm sorry you've had such a bad experience. I'll be happy to help with this. Can you post your helpdesk details? You'll find them in Troubleshooting/Helpdesk on the web interface at http://192.168.1.254 or http://bthomehub.home. Once you've done that can you run the speed test on a wired connection and post the results?