*Need urgent advice* Defect before handing over

Hi all,

I hope I can get some advice from someone here. Here goes, prior to handing over of house from ID to me, we went through defect checks, so most of the stuffs being surfaced are rectified except for one chink; i spotted a small ding on the window glass (near the corner). I highlighted to my ID stating that the ding damage was not caused by us as it wasn't there when we last checked. His reply was that he can try to resolve most of the defects except this (replace the glass). Reason being, 1) reno take too long already, 2) it is unsure whether his guys even cause this as people doing delivery can damage it as well. 

Given the situation above, i am unsure of the next step. Is it my right to ask for a replacement or as what the ID suggests, there is a limit also.

Appreciate any advice given, please.

Thanks in advance!