Very High Ping

[#1]

Hi.
Can someone at plusnet please have a look at my fibre connection, and tell me why my ping has been so high for the past 2 months (in comparison to what it was when I first got it)?
It's currently sitting at just under 40 (on a BQM graph) - this is double what it was when I was on adsl2, and a good 10-15ms above what it was when I got fibre last November.
I really notice this in online games, where I am a good 20-30ms above everybody else from similar locations.
As an aside, I notice my rock solid 37 meg connection is dropping to a very low 5 meg during the evenings again. This happened to me last November, and was eventually resolved as an issue at the local exchange. Could this be happening again? If so, I guess I would need to raise a ticket for this one to be investigated?
Cheers,
Lee.

[#2]

Your current profile is "0.128M-80M Downstream, Interleaving Low - 0.128M-20M Upstream, Interleaving On" so the interleaving that's been added will be the cause of your higher ping times.
Unfortunately that will have been added by DLM and there isn't any way we can get that took off. Depending on what's caused it to be added it may remove itself in the future but that's down to DLM.
With regards to the exchange congestion we'll need you to raise a new fault as I can't see anything reported at your exchange from our end here. If you go through the steps using the link below when it's happening our Faults team will look into that for you.
https://faults.plus.net