Welcome to the forums, I am sorry to see you have been having trouble with your connection.
I have taken a look and it seems there are a few things going on here.
Firstly it seems there is a little bit of trouble with slow speeds on the up-streams during peak times. I have raised this to networks and will let you know as soon as I know more.
Secondly it seems that your your upstream power levels are a little on the high side. I would like to get an engineer out to get this corrected for you. I will pop you a PM to get this arranged. Keep an out for the Purple Envelope, top right hand corner.