Part Time jobs for Dependant Tier 2 child employment

[elfgirl]

My son is 15 in Year 11. Quite a few of his friends have weekend jobs. We saw a sign on the high street and applied for a Saturday job waiting tables at a cafe. He works 4 or 5 hours during thier brunch shift each Saturday. he'd been there 2 weeks when we received our Biometric ID cards swtiching us from a PSW to a Tier 2 and found that it was stamped Work Permitted from 16 Only. Does this include part time jobs within the parameters set out for child employment on the direct gov website? I know on my student visa it said No Employment but you were allowed 20 hours a week. I've searched all over Home Office website.

any replies on forum or pm welcomed! thanks!