Active job

Fence inspection and ? Fix

Hi I had a x2 timber gates put in by Chris Long Building and it cost me $3000 and one has dropped after only a month. He came and mended it but it has dropped again and can’t be closed up. He’s saying it is because of an existing post even though he put new posts in for the gate alone. How much would it cost to just have this looked at by a professional as I’m quite upset I have paid this much and am not receiving the right help from the builder. Thank you