Sorry to hear about your situation. Skin elasticity is a factor. And sometimes the pocket is a factor as well. If the trouble is a pocket that is too large, that may allow the implant to hang lower or to the side. This can sometimes be corrected with internal stitches to the pocket (I usually us permanent suture for this). In more difficult cases, Alloderm can be used as a support material to help hold the sutures in place, and to help keep the implant in position.
Best of luck.