Yes it is an "up to" but it shouldn't be a problem on FTTP due to the speeds FTTP can support.
Well, what another 'BT left hand not talking to the right'.
After calling yesterday and reporting the fault again, I was told an engineer would be out today between 1pm and 6pm and they would call to let me know a time. When this did not appear on the 'Fault Tracker' I called to make sure it was booked. This was when I was told that no fault had been raised and an engineer had not been requested.
So today at work I got a call, wait for it......... no, wait.......... yep you guessed it, Openreach engineer.
Matt the engineer came here at 2pm, checked to see if my router was faulty by swapping it out. Checked on his system which he showed me said 80/20 so he called technical. He put the chap on loudspeaker so I could here. The conversation basically went like 'ummm, I see that..... oh hang on..... ummmm, what the...... ummmm, well, I have no idea what has happened but the circuit is in a total mess, I've never seen this before so I'm going to have to re-build.' 3 re-builds later same issue. He said he'd call wholesale and call back. He called back as, as you've already guessed, there was a provision issue. With that fixed and another re-build, a reboot of the ONT, my speeds are perfect!!!
I'd firstly like to thank all for your help on here and advice. I would also Like to say thank you to Neil, the forum mod that called me.