Thanks for guidance Sebastian.
I thought, I have to pay whole amount again and then only I can re-appear (2nd attempt) for the certification.
Following is the snippet of email received from examity.
HI @Neelinder , I don't now if your org has partner status, but I suggest that you contact your local Dynatrace account manager for possibilities..
If you're a partner I can only but recommend to attend the next Amplify event.