On the positive side and whatever the problems you are having, a drum brake on the back is less hassle in the long run than a disc. Just think no 2nd lot of brake fluid to change and be a PITA to bleed, no calipers to sieze up and overhaul and no hoses to replace.
IMHO a drum brake is the thing to have on the back and the good news is that when you get these brake shoes sorted they last a very very long time. You'll probably get another 45,000 miles out of them.