"Why haven't they sold them if this is just a share selling scam?"
You're asking, if PTOI is a scam, why CEO Mr. Heddle hasn't done more to screw over investors?? Here's another question: If PTOI is legitimate, why hasn't he done less to screw over investors?
I can guess that at today's volume, selling even a million shares would take a really long time and probably drive the share price down to a penny yielding maybe $20k...whereas selling debt to investors last year yielded $600k. Maybe that's the reason.
You could try to get to the root of the issue and ask Mr. Heddle how well the process converts anything into something of a higher value. So far that's been a secret even though Mr. Heddle knows all of those answers from the processor runs in 2013. Asking other posters to hypothesize why Mr. Heddle isn't doing something negative can't be as effective as asking Mr. Heddle himself what obstacles are stopping him from producing positive results.
Yes, I understand your penny stock also is the real deal, created with the inventiveness of Edison and destined to be the next Microsoft. Yes, I understand that the delays are also only because your company is making their product and/or technology even more revolutionary.