Ibpd, you and I share the same background, and I understand where you're coming from completely. That obligation to do everything to get the job done in a highly professional manner, despite unrealistic, unprofessional expectations from above and outside.
The RCA description clearly portrays it to cover working when the regular is off: Saturdays, sick and vacation days, etc. As retirees this sounded very doable, and a way to get out from under that health insurance nightmare.
Like you, I've been asked to fill in some on an additional route, the only other rural route in our small office. Unlike you, my PM and everyone in our office realizes that the RCA position is almost impossible to keep filled unless everyone works hard to not overburden them.
I've been fortunate. I'd say I work on average about 7-8 days a month. On mine regular route, I'm out by 8:30 to 9:00; back by 1530. The days I have to work the 2nd route the casing slows and frustrates me. Don't get out till 9:30; and to me that's a bad day.
Though I don't come out and say it, I think its understood at the PO that I didn't sign on for more than this, and I've never been pushed. I wouldn't have lasted at what is being asked of you.
That brings me all the way back to a topic that is always on my mind. How did our health insurance crisis ever reach this level? Why do some pay more than a mortgage every month, and some nothing, ever? You plan, save for 30 years, then this wrench hits just when you try to reap what you've sewn. Rant, rant.
Anyway, I feel for you, and don't blame you one bit if you toss the RCA thing back at them. Its poor, probably incompetent personnel management. Not your fault, and no loss of face.