Where can I find and buy a permanent hair removal cream?

You probably can’t, sorry.

And if you can I’m sure you don’t want to be playing with that stuff. Since the part of the follicle that grows is so deep in the skin to do enough damage to it would require a very powerful and possibly caustic substance that may very well give you second and third degree chemical burns on the skin surrounding the follicle.

Electrolysis, laser and scaring are the only things I know of that permanently remove hair and they do so by destroying the root irreparably. Any cream that can destroy a root irreparably is kind of a scary thought.