I joined a debt management program. All of my creditors agreed to this program but 2 of them. Which they went as far as turning over to a collection agency and then a lawyer. But, during this process the debt management company has been sending payments and they have accepted them for the last 6 months. Do I have any legal ground if they try to garnish my wages because a lawyer has contacted me and threatened me with garnishment?

Legal ground for what? To lose because you owe them, if they did not in writing agree to a payment plan, merely accepting money owed to them does not mean they can not sue and get a judgement and latter garnish your wages.

This is the issue with debt management if all of them don't agree and sign onto the plan, often one or two lenders can ruin it for everyone