Interest under section 220(2) on short deduction of TDS
I was going through a TDS CPC notice today. They have demanded TDS on account of short deduction, Interest on such short deduction u/s 201(1A) and interest on late payment of TDS under same section. They also say that such intimation shall be treated as demand u/s 156. The point of confusion here is that they specifically demand intt. u/s 220(2) on late payment of tds amount if such payment is not made within time of 30 days of service of such intimation but they don't charge such interest on short deduction of tds and ask to recalculate intt. u/s 201(1A) on such short deduction in case payment is made after the calender month in which such intimation is passed gets over.
Why not 220(2) intt. is being charged on the whole notice and only on interest on late payment of tds?