Speeds too slow to play games

[#1]

Hi, I have been with plus.net for a long time now but recently when it hits peak time (pretty much 4pm on the dot) until midnight, games have become utterly unplayable. Up until 4pm it is okay but after that it just becomes impossible. The ping within games is still pretty much what it is during the day, however, games such as TF2 and Left4Dead will stop and "Warning: Connection Problem" will occur just about every 10-15s on the dot. The pauses in the game last up to 5-10s as the connection is obviously struggling with the data.
This has been a recent problem, as games have usually been playable all day, even during peak times but now, the only times when I can actually play games during the day (i.e. after work) is now not possible. I just ran a speed test (from the plus.net site) and obtained a maximum of 132kbps download and 80kbps upload speed.
Can anyone offer some assistance?
Thank you.

[#2]

As you say there is something badly wrong.
Can you provide the following information
Router stats - attenuation, noise margin, speeds (this is how to get them http://www.kitz.co.uk/adsl/frogstats.php )
Report from here https://portal.plus.net/my.html?action=data_transfer_speed
Product you are on and the usage this month

[#3]

I seem to get lag to, well ping spikes, games just feel sluggish and stuff with it.

[#4]

Router Info:
DownStream Connection Speed  5504 kbps
UpStream Connection Speed 448 kbps
Line Attenuation: Downstream 31 db    Upstream 8 db
Noise Margin:  Downstream 5 db    Upstream 21 db
Report from link (taken at 00:06):

Estimated line speed:
    Not recorded (service activated before we introduced estimates).
Current line speed:
    4500

[#5]

what package are you on?

[#6]

@tengis, you're on our older Broadband Plus package.
From here.
[quote author="The Plusnet website"]How much can I use?
Broadband Plus is designed for a maximum usage of 4GB peak times (4pm-Midnight) and 50GB offpeak (midnight-4pm) in any given month.
If your usage goes over 4GB per month during peak or 50GB off peak, your service will be heavily restricted until the start of your next billing month when your usage is reset.
Take a look at your usage for last month and you'll probably find that the above explains what you've been seeing. Your usage has just been reset so I'd imagine you'll find that everything's back to normal again tonight...