Интерфес к БД

I accepted the developer's bet because, looking at his reviews and work, he seemed to me a good specialist.He called a fairly short time, which could not be unhappy.However, when receiving the first version of the project, the executive took the attention to the fact that the main points of the assigned task (3 layer architecture, role distribution) were not fulfilled.He received a very quick response with a message that the developer "destroy files by layers."He received the second version in 20 minutes, where nothing changed except adding new layers without any meaning.Again, I paid attention to this defect, which I received an offer to pay the executive half of the value.However, I do not consider the task to be completed even for half, as the main tasks, namely "realizing the 3 layer architecture" and "distribution of roles at the PL and BD level", were not completed.After my message that I do not agree to the offer of payment of 50% of the total cost, the developer did not answer anything by reading my message.I believe that the project has been completed with a haliture and emphasis on the customer's ignorance of the subject area, so I don't recommend the developer