Speed issue unresolved for more than a month.

Absolutely terrible from Supersonic. I've been experiencing a drop in speed every evening from around 6pm for more than a month now. I've not agreed to be throttled when signing up with them, and I hadn't been throttled before. When I eventually made contact, all I was told was that there is a known issue and that technicians are "working on it". This was more than a week ago from this post. I'm appalled at the fact that they are not contactable after 5pm despite the fact that their service, technically, is 24hrs. I have to take time out of a busy day at work to try and get hold of someone.