I trust you have raised your concerns in writing to the person(s) responsible for electrical safety and fire safety in the building ? Oh yes, and keeping a copy so you can show that it was known about should another Grenfell happen.
Also, if there's any evidence that the contractors were members of any scheme, then report them to the scheme(s).
Also, if there's any evidence that the contractors were members of any scheme, then report them to the scheme(s).