Honda PCX 125 Rear Shock Absorber Issue

Hello, I purchased a 2023 model PCX 125 scooter from a neighboring dealership. Since the day I bought it, I've been experiencing severe knocking and excessive flexibility in the rear shock absorber. I've reported this issue to both the Esengül dealership in Şişli and the Doğu Batı dealership in Ümraniye. They claimed that this is a chronic issue with PCX frames, which is not true; no other PCX has this problem. They refuse to replace it under warranty. In fact, the owner of the Esengül dealership, Mr. A**, suggested that I install an X-Max 300 shock absorber to fix the issue. I'm seeking your assistance in resolving this matter.