I do wonder at times if any if them know what they are doing. This recent Screwfix cock-up being a fine example. In the past I've had endless fun with BT, Virgin and TalkTalk. No effing commemt about any of them!
In the early days of home ADSL I spent hours on the phone to customer help desks on behalf of my customers- Talk Talk were by far the worst. I oft had to tweak TTL (Time to Live) settings on their MODEMS just so that customers could access Hotmail.
Unfortunately, it is pot luck who you speak to. If you are lucky, all of the lower grade techs reading a script will be busy and you will get through a more knowledgeable member of staff.