Welcome to the forums, I am sorry to see that you have been having trouble with your connection.
I have taken a look and it seems that you are affected by fault ref F004147201 for slow speeds at peak times. The current review date is 05/07/2017. I will pop you a PM to discuss this further. Keep an eye out for the Purple Envelope, top right hand corner.
Additionally I can see that your downstream power levels are too high. I will discuss this with you in the PM also.
Just an update. the engineer called and had us running at 100mbs in no time. He explained the issue to my wife and said it was all fixed.. Two hours later back to 5mps and has been like that since.
You mentioned that our downstream power levels are too high and we would discuss. Did we? I can't remember
Am I just stuck with rubbish broadband until the repairs?
If an engineer has visited they should have fixed the power level problem and your speeds will have improved outside of peak time. Due to the high utilisation in your area speeds will still fall in the evening.