You do not state the caliber of your pistol (.38 Super, 9x19mm, .45 ACP, etc).
Contact Numrich Gun Parts Corporation. They may have some that are not listed. Get on a wait list, at least.
Magazine, 9mm, 15 Round, Blued, New (Factory) Product #: 1410930A
Numrich Gun Parts Corporation
226 Williams Ln.
Kingston, NY 12401
Here's a new EBay listing for one in .45 ACP.
[Only registered and activated users can see links. ]