How do you know seller hasn't shipped. Not all sellers purchase labels through ebay or remember to mark as shipped.
If item hasn't arrived in 30 days and seller is not responding , open an item not received claim in the resolution center of your PayPal account.
Busy sellers do not always respond to have you shipped my item and 30 days is not uncommon for items from Asia. Have 45 days to file and best to always file no later than day 43 from payment date.