AIRx Filters Dust 20x36x1 Air Filter Replacement MERV 8 AC Furnace Pleated Filter, 6-Pack

I ordered a half dozen filters and when I received them realize they were the wrong size. I immediately sent an email request asking them to allow me to return the ones I received and get new ones. They emailed back saying they would respond within 48 hours. It's been five days. I've received no further response. They were not an inexpensive purchase all they were. They were less expensive than the supplier I was using. I was hoping because it was a Walmart affiliated I would get good results.