Can't recover "Firmware upgrade encounter"?

[mya cander]

I need help, I was trying to root my galaxy s3 (SGH-T999L) to get kitkat because t-mobile wants to be douchers, and not give us this update. Now, I have no idea what I was doing and I ended up clicking the wrong video and almost rooted it for 4.2 and not 4.3, me not thinking or knowing anything would happen, I went to the correct video to root it for 4.3 when I did, it said fail and did not complete. I tried to take my phone out of download mode thinking it was gonna restart, and it says "Firmware upgrade encountered" it says to recover with kies, but when I started to accidentally download the wrong rooting, I deleted it and reinstalled. So my phone was not connected to the kies after I reinstalled it. Now I'm worried I wont be able to get my phone back to normal. Is there some way I can fix this??

 

[Rukbat]

Get a 4.3 TMobile ROM and follow our guide, [Samsung] How to flash Stock ROM via ODIN. You can find the file at Download firmware: T999UVUENC2_T999TMBENC2_TMB - SamMobile (It's really a boring process to flash it.) Once that's done, the phone should start telling you that there are updates. Let it update to the version you want. (If you want to root it, you probably shouldn't go past 4.4.2.) Then put it in Airplane mode and root it. You'll still get update notices, but the update will "fail" (actually it'll just stop) on a rooted phone. If you decide you do want the next update, flash the latest ROM available at that time and the phone will start doing updates again.