You got your car, pay me back

I rented your car paid a deposit, signed an agreement as to when should I return it which was a period of a month. In less than a week you requested your car back. One of the conditions was that I return the car with full tank. I didn't have money then, I had to borrow just so that I could wash the car and fill in petrol. I returned your car immediately you promised to pay me back my deposit in a day or two. This is a second week since I've been waiting for my money. Pay back my money i need to refund mashonisa before he comes after me.