Awaiting payment please assist

I modelled for sync models last year for a ABSA gig everyone who did the gig with me got paid within the 3 month time frame , they were all from different agencies yet sync stated the client did not pay which I found was untrue as I reached out the the client and they had stated the payment was made this was last year august sync has not said anything and have still not been paid for a tv adverti*****t I did with sync and absa