Your upstream power levels are high and there are quite a few T3 errors showing in the logs. This suggests a upstream impairment on your local circuit.
This may not be the sole cause of your slow speeds, but definitely needs looking at by VM. It is possible you may have a contention issue as well, VM can check the local traffic on your network to check.
You will need to contact VM for resolution, either by waiting here about a week until a VM Forum Team Member picks up the thread, or give them a call on 150 from a VM line or 0345 454 1111 for a quicker response.
Thanks for the reply, run a test this morning and its back up to a more respectable 170Mbps, could it be peak traffic throttling or do I get VM to take a look at the connection?. I`ll clear the logs and start again