The junction of the A453 and Slade Rd is being modified to prevent a right turn from Slade Rd onto the A453.
Plan of the new junction http://www.staffordshire.gov.uk/transport/staffshighways/roadworks/schemeinfo/lichfield/Slade-Road-scheme-detail.pdf
Hi there and welcome to the forums! :mrgreen:
You seem to have dug up all the relevant information here. From the conversation you had with the reporter, it sounds like the no-right-turn into Slade Road is only temporary, due to the roadworks. I’ve also checked on Roadworks.org, which says that the roadworks are scheduled to end on the 11th.
I’ve downlocked all the segments to 1, so you can have a try at fixing this yourself. Probably the best thing is to change this segment to one-way heading NW. Then, for the right turn into Slade Road, set a time-based turn restriction to disallow the right turn up until 23:59 on the 11th of December.
Give me a shout when you’re done - or if that all sounds a bit too complex. 
I can then review and restore the auto locks.
You’ve obviously found the UK forum already, which has plenty of useful information and is a good place to ask for help. The UK Wiki (link in my signature) also has lots of rules & guidelines tailored for the UK. Lastly, the editor chat (icon in the bottom, RH corner of the editor screen) generally has somebody around to help. :mrgreen: