Unfortunately, BS7671 does not have a code for instances where statutory requirements are not complied with.
It is a statutory requirement that the staff and cleaners should be what BS7671 regards as either skilled or instructed, if they are to use the socket-outlets.
Regulation 16 of the EAWR:
Persons to be competent to prevent danger and injury16. No person shall be engaged in any work activity where technical knowledge or experience is necessary to prevent danger or, where appropriate, injury, unless he possesses such knowledge or experience, or is under such degree of supervision as may be appropriate having regard to the nature of the work.
By applying ay code, you are effectively accusing the company of breaking the law.