PIA airline scam

My flight ticket stated I’m allowed 28kg a suitcase. When I was going back from the Lahore airport, they claimed only 20kg is allowed and to now pay 1 lac 40 thousand rupees. We went back and forth for so long and there was an hour left before my flight boarded. At the end, they agreed upon 70 thousand rupees. I had no choice but to pay as taking out 8kg per luggage bag would have been insane and they weren’t letting me go. They didn’t give me any proof of payment for the money I sent and were demanding cash so I transferred through my bank instead so I had some sort of proof.

Is there anything I can do now?