Panama Postal Service (Panama City)

Does anybody else here find the postal service terrible? I have been waiting for several small items to arrive from USA for well over 6 weeks, still nothing. Am i missing something? Is it normal just to give your standard address or do i have to go to a post office to ask and collect?

I've also sent several items to the UK and nothing has arrived. This was about 8 weeks ago.

I'm starting to think there is something i don't know about how the postal system works in Panama, and that my stuff is just sat somewhere waiting for me to do something, which i don't know about.