Qatar Airways complaint: extra hand carry charges

On 11th May 2024, Flight number QR831 , Booking reference:QR/ VB4PXX , Boeing 777-300ER, me and my husband flied from BKK to DOH.
I understand that Qatar airways allow to carry 7kg (hand carry) for each person. Me and my husband’s hand carries were 10kg and 9 kg each. So far as I understand , hand carries should not be considered as baggage claim and carried along with passengers together. If hand carrier are overwieght, they should charge over weight kg only such as ( 19kg -14kg 5kg @ USD 30) or allow us to reduce weight till 7kg. However, check-in counter staff not allow us to reduce kg (with the reason of shortage of time. That also their check-in machine got problem and they allow to check in same time for both flight QR831 and QR839), not allow to carry with passengers and weight together with baggage and charged us (19kg @ USD 30 equivalent Baht 21,660).
However, some other passengers can carry thei hand carries along with them.

Due to the above reasons, we realised below:
1. Ground operation service is not consistent for all passengers
2. Charge to us for whole hand carries charges (19kg) instead of charging only extra (5kg)
3. Consider hand carries as Baggage and weight together without our concern
4. Not allow to exercise passenger right such as to reduce hand carry weight till 7kg and not allow to carry with passengers with the unreasonable reason such as shortage of time ( that is not passenger fault).

Please kindly verifiy again and compensate our extra payment of hand carry charges (19kg -5kg 14 kg@USD 30).