The truth is that there isn't any consumer-grade telecoms/ISP provider that doesn't have awful support. You need to go enterprise-grade for any kind of competent support, but the prices will follow as well. Only exception to this would be A&A when it comes to DSL, which offers great & competent service at somewhat affordable prices:
https://www.aa.net.ukYour best course of action is to never sign up to a contract (use the 30-day rolling plans) and be ready to switch at the slightest issue. For home/fixed-line, consider having 2 providers for redundancy so you don't lose connectivity while switching.
