Disgusting service and disrespecting customers

They are good selling cars but terrible in keeping their word for trade in settlement , if you dont follow up they won't give you feedback. When you call, they will tell you excuses as I was told that settlement will be processed within 3 days (22 December 2023), but now its been almost 2 weeks (10 January 2024). The have even sold my card without paying settlement. I feel emotionally tired and disrespected. Any advice on how to go forward. I am done calling them to do their job. Please those who have Twitter please help. I feel is time to involve the police and lawyers because what was suppose to be a happy time for our family when trading in my car became a nightmare.