Tube Problem

Anyone had this happen before? I got a new set of latex tubes the other week, drilled my rims for
them and they fit perfectly. I had one tube that didn't want to accept air just right, but it gave
in and finally did. So today I decided I wanted to put a little slime in them and the one that I had
problems inflating would not take a drop of slime. So I decided to just air it back up. It wouldn't
take air again, and this time was persistent in its refusal. I got about ten pounds in in, removed
the valve core and the air would not come out. I messed around inside the valve with a center punch
to maybe free whatever was blocking it and got nothing. I finally got to the point to where I was
hammering on the center punch and still nothing. Needless to say the tube is useless. Anyone ever
seen this, manufacturing defect or what? Normally I would just have tossed the tube out without
thinking twice, but these were a little pricey.