Itr - query

Hi, 

Background: ITR filed on 30/5/2019 and e verified the same, Assesse identified errors and submitted revised return on 26/06/2019 which impact refund reduced by Rs.3000/-. Assesse did not e-verified yet, however assesse get refund on 03/07/2019 

Questions

1. How to pay additional tax liability of Rs.3k

2. How the revised return impact as it is showing refund amount 

3. Can Assesse ignore revised return as it is not e verified and amount of tax is insignificant 

Thanks in advance 

Regards

Ashok