Minimum Stars - Feeling of being ripped off!
Every three months BT sales call and try win back my business - honestly I would not go back even for free.
When I moved house I got "conned" into a featureline I didn't need and a business internet connection that didn't work and couldn't be fixed by BT's own OpenReach team due to internal office politics.
After months of hassle (and lack of internet), and only after threats of legal action, BT allowed me to change internet providers, of which the new ISP got my internet working in a single visit!
BT also tried to lock me into a 5 year featureline package with a very expensive buyout, lucky I found an alternative provider who covered this cost.
I still get the phone calls every few months telling me they will give me a better deal, but the better deal always costs more than I'm paying now and based on past experience no way would I consider.
BT - unless you can offer me super-fast internet that no other provider can - here's one unhappy ex-customer quite unlikely to come back!