Payment issues

I had a terrible experience working with this company. I was doing promotions for this company on black Friday (29 November 2019) and prior to the actual work we had to go for training. At the training we completed all our contracts and the supervisor in charge promised us that we would be paid 3 weeks from the day and nothing later than Christmas. But unfortunately I am still waiting to be paid. I got in contact with the supervisor to see what the situation was and she just gave some terrible response and said that we will only be paid on the 10th of January. And some people actually need the money going into the new year. And this is just unacceptable and to be honest it's just poor business practice.