I'm sorry if this has been asked to death......

Somebody won a bid on Saturday and still hasn't paid.

I realize that ebay auto sends them reminders after a few days, but I'm not sure when and how many reminders they receive.

My question - is it better to send them a private message or send them another invoice? 

I can't see any type of 'reminder' notice to send them through ebay.

Cheers!