It seems that even though you paid the fee, KEA’s system did not register it properly. This can happen due to payment gateway delays or technical issues on the KEA website.
You should immediately contact KEA helpdesk to resolve this. Explain that your payment was made, show any bank transaction or UPI reference, and mention the WhatsApp message about the failed payment. Also tell them you cannot download the receipt from the website. They can verify your payment and update your application status.
Official KEA website for help:
https://kea.kar.nic.in/
Application | Eligibility | Admit Card | Answer Key | Result | Counselling | Dates
Regular exam updates, QnA, Predictors, College Applications & E-books now on your Mobile