Employer refuses to pay because of no work available

I have joined a company (Say X) as Exempt salaried employee and was supposed to work as contractor to another company (Say Y, with whom my employer is supposed to have contract with). I resigned my existing job and joined the new company. But the contract with other company kept postponing. I was getting paid by the company X (also did perform work for them for few days). One day I was told I was taken of payroll (not terminated) and they will not pay for past 3 weeks and further down until they get the contract squared away with company Y. I got notification about this until after the fact. They have been saying work will start next week, every time. They never respond to me promptly.