Family Dollar

On 01-16 2021 I purchased Two Gift cards per a so called Hewlett Packard Engineer. He said he needed the code numbers from the back of these cards to ward off hackers who were trying to get into my accounts. After he used the numbers he said he would the refund the money back to my discover card. that never happened. These chargers are still pending at this time. 01-17-21. Can these charges be removed and my money credited back to my discover card? Store # 02425 Alliance Oh. where the purchase was made in the amount of 401.35 last four digits of credit card 2541. Thank You [protected]@aol.com