I subcontracted to an HCR Mail Carrier to cover her delivery route via verbal agreement for $100 per day. I have since found out that the average rate is $250 per day. But that is really irrelevant. She has since refused to pay the full amount she owes me saying that her total rate is $100 per day and that she did not say that is what she would pay me specifically. So because they had to bring in other mail carriers to train me because of her sudden accident prevented her from doing so; I would have to split that $100 per day with the people that trained me. That it is not her responsibility to pay them above and beyond the $100 per day that she agreed to pay me. Now this is not an exact number, but I believe she still owes me a minimum of $500 and she is refusing to pay me. What do I do?