I'm very surprised and sorry to learn about your experience with the nursing school. It's actually very odd and unlike nothing I've experienced myself or heard of about Excelsior!
I was going to recommend that you check out Louisiana State University's English Composition course:
LSU Independent and Distance Learning
But I can see that the course is on hold, apparently due to the unavailability of the required books. The web page says that LSU will allow enrollment if one manages to acquire the textbooks. It also says the course is being revised, possibly to use other books.
The cost of the course is $241 excluding books. It involves relatively more work than Penn Foster's (15 assignments and 2 proctored exams) but is still a bargain.
If you're interested, you'll probably have some luck locating the books second hand on the boards here, I'm sure quite a few have taken the course. If you run a quick search on the boards you should find some feedback.
Another affordable alternative would be taking the course at Clovis Community College:
Spring Schedule
Apprently it is $113 (without books, I presume) but I have seen no feedback about this course. It's seems to be regionally accredited (I'd verify that).
I'm still baffled as to why the nursing school had refused approval, maybe it has something to do with the way their program is accredited?
Wishing you luck...