Hello aspirant!
Hope you are doing well!

If you have made the mistake of making payment twice, you would have to inform the authority about it to get a refund. You can mail them in their official email , siting your issue along with the details of payment. The reimbursement of the money mostly takes about 7-10 working days.
Hope this helps!

Dear student

Yes, you can. To get your money refunded, all you have to do is approach the financial custodian after 15 days of closing of Registration Window. The Financial custodian will refund your excess payment, within 15days of receipt request from you.

My advice is you stop worrying and apply on the right date and relax.

Hope it Helps