re-tensioning springs

Hey,

I bought some new rear srings for my Midget from, well you know where, and
they've gone completely dead-flat in less than a year.  I can most likely do a
warranty exchange, but would it be better to get the ones I have in there
re-tensioned?  I'm thinking no, since it might just be bad metal, but I would
value hearing others' opinions.

The springs are for a 1500 Midget - half moon shape, or at least they were.

Thanks a lot,

John Gottstein