Casino disputing my win on the grounds that that max withdrawel had been reached

Casino: Gibson

Claim ammount: 1500 AUD

I deposited 300 on a no wager bonus promotion & won 6800 $ I instantly withdrew 2500$ because that was the max wthdrawel, I left 2500 in the cashier & assumed I would need to wait for a week until the cashier would allow me to wthdraw the remaining 2500$ I checked back about 3 days later & to my surprise the cashier allowed Me to wthdraw a further 1500 of the 2500 $ sitting in the cashier enitialy they just never paid the 1500 to me & I made a complaint to accounts manager Samantha, & had some words wth her about my missing 1500 $ she then went to management & came back saying they had done an inquiry into it & that they would pay the 1500$ minus the nwb,, I have emailed her multiple times now since wth no reply can you please assist me in receiving my winnings from this casino 🙏