Bad customer service

I have been trying to contact Matrix to remove their unit because i sold my car.I managed to speak to one of their customer care then she said they will come the following day , they never phoned , they never came , i sold the car and sent them mails , still they do not want.I wonder why is it they do not assist , what if i was getting ****** and they do not call me back. I sold the car at We buy cars and the dealership informed me that Matrix have 2days to come and take the unit. Until now they havent been intouch with me.