Struggling to book a maintenance om a faulty unit

I phone them a month back , when i saw that my one car tracking device are not updating. Then i phoned them again yesterday and after 26 minutes on the phone. They said the maintenance scheduling department will phone me to schedule my car.

Today at 13H00 i phoned them to book a schedule , they told me they can only help me on monday .. that is when i must return to work again. I ask that they find a way to help me before monday. Or even monday morning at 8, because i must be leaving at 10 monday morning. They must please let me know before end of business today. The unit in my car worked for mabe 2hours the day they installed it. It is as off today 138 days later . But i must just keep on paying.