Well, the good news is your levels are now within spec and looking good.
The bad news is you are fully connected to virgins network.
The massive latency spikes are something I have too on my 1gig line.
It's not it's normal or good.
I have been trying for months to get mine fixed.
IF over utilization is the issue it may take months/years to get fixed.
In a nut shell, too many people are connected in your area because virgin oversold.
Either that or there is some sort of noise on the line, that may also take months to find and fix.
If you are still within 14 days and there are other providers available, I would run while you still can.