Refusal to pay for services rendered

My company rendered services to this particular company. The owner contacted me and requested assistance with sales outsourcing solutions. The area agent went and assisted for a week. We work on a 50% deposit due to the nature of our business and exploitation in the past. The client was reluctant to pay the deposit we agreed and signed a contract to proceed which was an obvious risk for us. To this day excuses and promises were made and we still have not received remuneration for the services rendered.