Can I be denied STD as an employee on straight commission?

my husband is being denied STD due t the fact he is paid o straight commission. He receives a W-2 and is an employee not a sub-contractor, but the Ins Co. is citing their requirements listed in the policy "basic wage does not include commission". He has been paying premiums for 12 years to this company, as are all the employees (none of them are salaried, they all are paid by percentage of what work they do). His employer and the lawyer who takes care of the company's insurance issues say they are working on the situation and that everything will be all right. Meantime, we are not receiving any income for the last 5 weeks.
Should we hire a lawyer and sue either the employer or the Ins Co. (for taking premiums from my husband for insurance that he would never qualify for?