Cognizant Technology Solutions — application on hold/ didn't receive any response till date

Hi, i interviewed at cognizant hyderabad last month and hr told me that i got selected and will be receiving offer letter soon but it's more than three weeks i received an email stating that am hold and after that u follow up but till i didn't get any response from them. Please help me with this. I left my last company and am an immediate joiner. Please do needful as it will impact my career.