The engineer said a few weeks ago that our line from the house to the exchange was fine.
He changed the phone socket for us and our speed leapt up to 18 Meg from 3 Meg.
Since then, our speed has been dropping dramatically, though (losing half a Meg in speed every day the last few days).
Our Talk Talk router has been disconnecting at 3 am nearly every morning - causing the reduction in speed.
According to our modem stats, we should be getting a speed of 15 Meg but we're only getting 4-5 at the moment.
I've received an update from our network team. This has been raised to to Openreach for a non-appointed task, we should receive an update within 72 hours so if you don't hear anything beforehand can you bump the thread on Monday and we'll check for updates