My door pocket would not stay closed. Instead of buying a new one, I came up with a solution.
I cleaned the surface with rubbing alcohol and then applied 3/4" adhesive backed Velcro fore and aft. Very cheap, easy and effective.

 

Mine did the same thing. Another solution is to pack the gap between the bottom of the pocket and the door skin with some appropriate sized foam weather stripping.

 

Beautiful, love these small fixes.