Sometimes, the client is dissatisfied with the quality of the service provided or the goods delivered. Still, sometimes there are no quality issues, and the question of payment is postponed. Many simply disappear and do not respond to claims. The first thing you should do - is asked in writing to justify the reasons for the refusal to pay. By doing so, you will record your own handwritten statement of the person, confirming that the service was still provided to him. This document will help you later for Debt Collection quotes or in court as evidence.