1. You yourself is highly unprofessional and do not follow the rules prescribed for running an unit like issuance of appointment letter, salary receipts etc,
2. You yourself claimed that the work procedure followed by you are informal,
3. You can not expect/demand that your labour class workers will be formal and follow the rules prescribed by you,
4. If they are not employed formally, they are not required to give notice for leaving your job,
5. Settle the matter amicably, since if they go to labour commissioner/court, you will invite unnecessary problems.