I used the MF9 stock recovery after going to MJA in order to do a factory restore. Then I used it again to manually force the update with the cce8d8a155a0602c83356e00311a1695e9a9383f.USER_L720 _SPT_MF9_CSB_user_RP_to_MJA_CSB_user_RP_Update_FWD .zip file.
Have you tried just doing an RTN via the phone dialer? Enter ##786# on phone keyboard, Select "reset", Enter MSL.
Both of those methods will wipe everything, of course, so backup using Helium, etc.
Samsung S4 (9505), Samsung S3, HTC Evo 4G LTE, HTC Evo 4G, HTC TouchPro 2, HTC 6700 (all Sprint)