"Complete(Write) operation failed" commonly occurs when you're trying to downgrade. That's weird, since you're flashing MJ7.
What does the phone say when the write fails? That's the detail that's needed to understand why the flash was rejected.
Why are you trying to re-flash? Why re-partition (the PIT file)?
I was just trying to upgrade it because the ota was failing. Just tried it again this morning and get this:
<ID:0/008> Added!!
<OSM> Enter CS for MD5..
<OSM> Check MD5.. Do not unplug the cable..
<OSM> Please wait..
<OSM> ALL_I545VRUEMJ7_I545VZWEMJ7_1937946_REV06_user_low_ship_MULTI_CERT.tar.md5 is valid.
<OSM> Checking MD5 finished Sucessfully..
<OSM> Leave CS..
<ID:0/008> Odin v.3 engine (ID:8)..
<ID:0/008> File analysis..
<ID:0/008> SetupConnection..
<ID:0/008> Can't open the serial(COM) port.
<OSM> All threads completed. (succeed 0 / failed 1)
EDIT:
Strangest stuff ever. Would not do anything on ODIN, try it this morning and its up to here and still running(<ID:0/008> system.img.ext4). Furthest ive made it yet. Will report back if it works. Only thing different I did was disable my antivirus.