mobile

I stupidly rooted my phone before taking the OTA update, and now of course I can't get the OTA because my device is modified. I just want to restore my system completely back to stock, but a factory reset doesn't modify the system so root is still there, and there aren't yet any stock firmware files anywhere for the Sprint S6, unfortunately. I've tried using Kies and Smart Switch to manually download the update, but of course our model isn't supported through that software. Is there any way to just return to a stock system? Or, did anyone happen to capture the OTA file before applying it?