7/11 cancelled recepit refund

Hello! Day 2 at Bangkok. So I was at 7/11 in Chinatown today, bought few items and paid 627 BHT using my debit card but due to change in items I got the whole recepit cancelled. A new recepit with -627 BHT was generated and countersigned by me. Now how long will the refund take to credit back in my debit card?