The trim parts you are most likely missing are the left trim 8302907, right trim 832908, and/or the bottom trim 8302947. These are the items that usually get separated from the units once they are out of the box. I would have expected the Lowe's employee would have taken care of this for you instead of referring you to someone else. Just my opinion. To get these parts, you will need to contact Whirlpool customer care at the phone number on the inside of your use and care manual and let them know what the situation is and where you purchased the oven. They will want your pertinent information, but should be able to take care of you.