I understand your worries, try contact seller at last time, send mu messege: when you not contact me or send me track number, I wait (for example 1-2 days), then I contact paypal and I want my money back.
Seller must proof paypal, that send package. Where are you from? and where the seller? Do not forget, Delivery time varies.
for example from US to czech rep....12 days, UK to czech 5 days, JAP to czech 5-10 days....SAL or Airmail or EMS,