Noc for Nursing MOH license

Greetings ,
I currently working as a school nurse but the company did not made any agreement and also my residence is not transferred under the company. I dont want to work anymore at school.Now i working under my old visa (article 18)only but my MOH license are proceeds to transfer under the company name and now they are refusing to give the NOC letter. Is there any law/rules to hold my MoH license under the school company even my residents is not transferred under school?