KDMC — Getting error after doing the Property Tax

Address:

B3-1202, Raunak City, Sector 2, Don Bosco School Road, Adharwadi, Kalyan (W) 421301

I faced this issue two times consecutively wherein everything works fine till the time payment is done, and the moment payment is done through net banking the next screen throws below error without giving me the receipt of the payment (screenshot attached for reference). I contacted by bank and they said that the payment is released from the bank to the vendor. So kindly help here to understand whether my payments were processed and why is the site giving error only after the payments are done?

"Warning
Sorry, Unable to process your request.
Please contact to Administrator and try again later!"