Signed up to these guys after they made some big promises.
I had 3 lines to transfer. I told them not to transfer one of the lines until the others were fully up and running as it had my current internet on there.
They didn't do that. Started my new internet with fibre being installed nearly a month later. Stuck with ridiculously slow internet that I couldn't work. In the end, had to add more data to my mobile contract as 3g was way faster than the broadband. Was told I would get a call from someone after she spoke to her manager, 2 weeks later still waiting.

Now they suspend your lines over the weekends when they are closed, I believe to cause the most amount of disruption to your business. When they offer compensation it turns out to be a lie as the never pay it (was offered amazon voucher never received it)
This year they signed me up for a 2-year contract without my permission in a very sneaky way.