No transparency on payments.

I am working for this company as a subcontractor and I am very unhappy with the service I received from the staff and I have been using my truck(brand new 1.3 ton) since from beginning of February this year.. I was not receiving the invoice to measure how I was paid. And I have been receiving almost same amount ever since I worked for your company.. there is no transparency between employer and subcontractor.. my truck it is used to travel to Johannesburg and other places but there is no difference when it comes to payment and it can deliver close to 55 parcels per day but there is no difference and your staff keeps on promising that I will see the difference the following month but there is no difference,I am wondering how you work because according to the contract we were supposed to get trip sheet to measure how the truck worked throughout the day but I have never received not even one. We don’t even get payslip/ invoice .. I feel that we are being exploited as we are only black people working for your organization at Klerksdorp branch. Other subcontractors are quitting every month and I also going to take off my vehicle of your services, Because it looks like you are the only party that is benefiting from it. I have sent an email and facebook message but I haven't received any response.