Where can I find platforms to add to a existing shoes with 4inch heel?

so I have these shoes that r hot hot hot, but the heel is so high and my arch is killing me, so I[ve seen styles of shoes that have a platform attached at the bottom, so I thought about doing that, but don't really know where to start. I went to a local shoe repair shop and they said they didn't do that? I need the shoes for a pre-superbowl event in Miami FL.