1989 Buick Park Avenue Rear Brakes

Can anybody help? I've got a 1989 Buick Park Avenue and have recently replaced the rear brake shoes and spring kits. The upper shoe return spring on both assemblies keeps coming out. I've already ruined one new drum because of this. I've tried to crimp the end of the spring that goes over the little metal bracket - (i'm not sure if that end is coming off first or not) to no avail. I'm beginning to think the spring may be coming out of the opening in the shoe (where the other anchor point is) first. Whatever is going on this is a new problem - the car has 113000 miles and the upper return spring on the left rear popped loose a month ago and started me on the path I now find myself on. Any advice or useful tips would be greatly appreciated. Thanks.