Rectification request against 143(1)

kindly check your demand notice once again.

Because in my opinion, while Processing returns, the Income Tax softwares take the value of TDS credit only from whatever is there in 26AS to your credit. so there shouldnt be any difference of that sort that you are mentioning. 

This can happen sometimes. The date of processing is important. At that date, maybe 26As was only 30000/- Also check whether you have claimed the 5000/- properly, TAN, etc. becos if there is a mismatch you will not get credit even if the same is in 26AS.

The procedure for recitfication is log in to your account. Chose option Request for rectification. Enter the relevant details ( the CPC intimation and details of all TDS deductions for that year must be kept handy). Under the rectification type option chose " tax Payer is correcting data for TDS Mismatch"

Now all the TDS entries will have to be entered TAN wise and submit.