I too have been suffering with poor peak time speeds over the past 18 months and was forced to upgrade to 200Mbps to get a 'useable' connection during peak hours. I have been chasing for a factual update but haven't got past the canned response stating the fault is due for review in 2 months or we are waiting for an update from the engineering team.
For reference, the area code on your account refers to a historical billing system and has no bearing on location. I'm in area 20 with a m33 postcode for the Sale area. I don't think this issue is specific to a particular circuit fault as people experiencing issues are all over the place. I expect VMs back end isn't coping with their sales drive and they are having to throttle bandwidth during peak hours. Interesting to note that at the chime of midnight I'm back to a full 200+ Mbps connection.
I would move in a heartbeat if there was anything comparable speed wise.