Correction of overbooked challan when there is an unwanted additional deductee

Hi,

We recieved a communication about over-booked challan. Actually, we deducted Rs.8000 TDS from salary in Jan-18. By mistake, we entered the TDS amount as Rs.8500/-. And the remaining Rs.500/- was assigned to another deductee who actually did not pay the TDS.

It happened so because the other deductee discontinued TDS in Jan-18. By mistake, I entered the previous month TDS details for Jan-18 also without verifying the BIN amount.

So, I have two problems before me. One is to delete the UNWANTED deductee. Of course, I do it by filing a revised return. But how to correct the challan?

Which one should I do first? Revised return? or Online Challan correction?

And the procedure for correcting the challan also..., please. 

Thanks in advance