I had a similar situation. The people on the phone don't seem to want to know about their possible network problems. The woman on the phone with me said there were no local problems and wanted me to go in to another area in a few days to see if it was the same. I'd been on the phone an hour by then performing all kinds of very basic tests. In the end I didnt bother calling back. I just setup my wifi at home for my phone to connect to.
Incidentally when I did go to another area the regular speeds worked fine again.
The problem they have is they refuse to accept there are problems in areas because they don't listen. So when you call up to say there is a problem they act like everything is fine, when for all we know 10 or 20 other people might have also called to complain, but nothing is registered officially.
I recognise that it could be seen as against the companies image to be registering faults on its service. But by just ignoring or dismissing people is only going to lead to more problems down the line.
It's getting annoying that these companies seem to treat people like thick idiots. Most people these days have a basic comprehension of technology. So unless they say they don't then why keep doing the basic things all the time, going around in circles.
Ok rant over