littlesew&sew -- "So the bid closed on the 8th. I was notified that I got the vacant route on Wednesday, the 12th."
-- Congratulations on making regular. You've may have previously visited ruralinfo.net to check out the "Rural Carrier User Guide" and "Rural Carrier Tip Guide". If not, do so.
-- 21 days to be placed on the route makes it about 3 October, a Wednesday, which creates a problem for the PM as carriers should be in place on the 1st Saturday of a pay period.
"Her response was that it's out of her control."
-- Might as well inform your Assistant District Representative of the PM response as well as fill in a grievance form.
-- As long as you are on the route as of Saturday, 29 September 2018, you won't need that grievance form.
-- Placing you on the route may be out of her control, but there should be a grievance form in her hand if you are not within 21 days.
-- If notification could be done in 4 days, what is the reason for the "delay" in placement?