How to file corrected tds return

We are using ZEN TDS software for filing TDS return. We have already filed Q-2 for AY 2010-2011 for Form-26Q containing 4 challans and the same was accepted by TIN (Tax Information Network). But later on, it is found the 2 challans entries have not been incorporated. After that we have filed corrected TDS return for Q-2 only mentionling 2 challan and earlier 4 challan entires have not been considered and it is rejected by TIN. As a result deductee is unable to claim for credit. My question is whether corrected TDS return has not been properly filed and please let me know how to file corrected return using ZEN TDS software. We have e-mailed to TRACES relating to this problem a week ago but no reply has come till date.

Please guide me to solve this problem.

Thanks in advance