Bath & Body Works Wall Plug-In Fragrance Stops Working After Weeks

I bought five or six Bath & Body Works wall plug-in air fresheners for my home. The fragrance refills are sold separately from the plug-in devices. I really liked them when I first started using them and was very satisfied. The scent filled the entire room and was very noticeable. However, after two or three weeks, the fragrance stopped spreading, so I tried a new plug-in device. The same problem happened again after about a week. I bought five or six separate plug-in devices and five or six separate fragrance refills, and all of them ended up being a waste of money. I would not have expected this from such an expensive, globally recognized brand.