Got scammed by delivery guy

So today I received a parcel via bluedart. The guy told me that I have a parcel of 2100, I was convinced as I know that the amount was 2 thousand something only so without checking the actual amount I went and paid the amount thinking usually the delivery guys return the leftover amount. After receiving the parcel, the guy almost started crying with folded hands that his mother is a heart patient and any tip would suffice. So our of kindness, I paid him 100 rs. After he left, I went inside and checked the parcel and what I saw was that the amount to be paid was scratched, so I checked the app through which I placed the order and the amount was 2076. The guy not only took rs 100 extra but did not return my extra money. It's not about 100, 150 rs but the trust. I felt very bad believing this guy. Has this ever happened to anyone else ? What am I supposed to do now ?

So today I received a parcel via bluedart. The guy told me that I have a parcel of 2100, I was convinced as I know that the amount was 2 thousand something only so without checking the actual amount I went and paid the amount thinking usually the delivery guys return the leftover amount. After receiving the parcel, the guy almost started crying with folded hands that his mother is a heart patient and any tip would suffice. So our of kindness, I paid him 100 rs. After he left, I went inside and checked the parcel and what I saw was that the amount to be paid was scratched, so I checked the app through which I placed the order and the amount was 2076. The guy not only took rs 100 extra but did not return my extra money. It's not about 100, 150 rs but the trust. I felt very bad believing this guy. Has this ever happened to anyone else ? What am I supposed to do now ?