mate, i don't mean to be rude but a replacement sim tray will cost you literally $4 on aliexpress or similar. What exactly do expect to gain from taking them to court? You won't even be able to "take them to court", best bet would be to quote the CGA to the retailer and waste even more of your time.
https://www.aliexpress.com/wholesale?catId=0&initiative_id=SB_20190724004745&origin=y&SearchText=LG+G6+Sim+tray&switch_new_app=y