check ur email. if you had bookd the tickets twice, you will get two emails. choose one pnr and cancel the other ticket. your ticket will be refunded back.
In case one of the transactions have been debited wrongly, irctc will refund back within 2-3 days, but unsuccessful transaction would also be intimated.
other option, open your irctc account and checkd in booked tickets history, you will see the dates and pnr numbers/transaction id. you can chk from there. dont worry.