Speed halved and no dial tone

[#1]

So i guess the two are linked? Plusnet are aware of the no dial tone and say it will be fixed by 08/01. However will my speed go back up again after this? Its pretty inconvenient considering I have no phone service and half of my internet speed  

[#2]

Given that you broadband is carried over your phone line you should consider yourself lucky to still have broadband if you phone is not working.

However your line consists of two wires, both are needed for a working phone, but broadband can give a slower service with on one wire.

So yes you speeds should come back, although you may need to wait a little or ask to adjust your proffile.