The demon fly of Glenhew Rd

There's a fly. In my house. It won't die. I've chased it, batted it, swatted it, sprayed it with every type of cleaner in my home. Yet... it lives on. I thought fly's lifespans were like 12 hours or something. This thing has been here haunting me for 3 days. I think all the cleaners are mutating it into super fly. Did I mention it's driving me BONKERS???