Many thanks for your time and advise. Looks like a return to a Peugeot garage.

 

Just looking through things, noticed this / may not apply to you ?

PEUGEOT 3008 (2019 - 2020) - REAR SUSPENSION FIXING BOLTS - Car-Recalls.co.uk

Only 30,000 miles... seems quite unusual.

 

Ok, so looking deeper into this for you (which is a bit hard because of year model) You don't have a case of misinformation in regard toe in-out for this model at the rear.
But there has to reason why, no longer at the set level, so a problem with the suspension itself, a worn component(s).

I think this needs to be looked into. Chewing through tyres is not ideal.

 

Rear toe is out of alignment

Generally, toe-in or toe-out is adjustable on all cars.
Are you sure ?

Camber isn't technically adjustable on most, but you can still do it.

Where is print out of before and after adjustment ?

 

Mechanic was adamant toe wasn't adjustable. Arranged is after alignment