Hi, I’m at my wits end. We are wanting to attach pantry shelves into the pantry with support beams underneath flush against the wall. Trying to get screws into the wall has been a nightmare. It seems like about 19mm in the wall are steel plates all over. Tried drilling hole first and using Buildex Tek Screws hex head higrip with impact driver. So far only one screw has caught on to the steel, it seems really hard for the other locations to drill into to expose the steel. Please help! Thank you.