Sdmc — Unable to pay property tax online

I am having dda flat in sector 19, rohini. While trying to pay the property tax for fy 2020-21, the ndmc portal shows that upic is already registered. When i press 'action' button to proceed for online payment, the message flashes 'upic already in use. Contact mcd'. It does not open the gate for proceeding with online payment procedure. I have been trying for the last many days.
I also understand that a few others are also facing the same problem and therefore, there seems to be system error/problem. My telephonic discussion with mcd officials in rohini also could not give any resolution to the problem.
Please resolve the issue asap to enable me to pay the property tax on time.
Property id[protected]
Upic - 0492414aveag601