Sorry I missed the call but thanks for all the help.
Seems to be much better tonight, mostly around 35-45mbps.
I'll keep monitoring over the week and let you know if it drops too low but it looks promising.
On another note, I got a text from BT and they wanted to send an engineer over to check my flat, I'm guessing that's not from you guys? I'm not too keen on the possibility of having to pay to have an engineer over so I'll just tell them it seems to be okay for now.