Employer Didn't Pay

Location: Maryland

My friend worked at a restaurant for a week. He asked for cheque but they said they'll pay in cash. He agreed and after working for a week. He felt too much of mental stress, there wasn't much work at the restaurant but the owner keeps saying things about his dress and skin color. Thinks like remove Bracelet and Silver Chain, The skin between you pants and shoes doesn't have to be seen and asked him to wear full socks. They kept pointing some kind of mistake and always had something to say. So he quit and they said think about it and he went home and didn't change his mind and quit the job. So first they said they'll pay $9 per hour for training and $14 once the training is done. Even before he said he'll quit they told him that they dont usually pay for training but they'll pay $7. After he quit when he asked for pay they just made it up and said you need to give 30 day notice and you left without replacing anyone. So we'll give you by the end of this month. This was in February and they keep ignoring his calls and text and rarely reply saying they dont have money to pay now. They'll zelle him whenever they have money.

Now my friend is not a Citizen but he is on a valid VISA and legally authorized to work. The thing is his work permit currently doesn't allow him to work at restaurant but he needed money so he did.

If he file's a compliant on the restaurant at the Maryland Department of Labor. Will that effect his VISA status or just solve the wage case and close it?