Income support ? Please advise!?

Been claiming jobseekers but now need to claim income support, they couldnt close my JS claim untill my employer sent me out my payslips, so my claim for IS has been denied because of it, even though the JS money was suspended and i recieved nothing. I should recieve payslips very soon, can i make another claim for IS and get it backdated to when i should have started getting it? Any thoughts welcomed, thanks .