International sales

[tvbookman]

I routinely set my ads up for NO foreign bidders for items under $100.  It is just too much trouble to make 2 trips to the post office (one to get the price and another to take the package which the mailman won't take)  and fill out a custom's form.  Not to mention the cost of gas, and I am a senior citizen.  Despite this I CONTINUALLY get bids from foreigners!  I cancel them, but the last time, I got negative feedback afterwards.  Why does ebay even bother asking if I want international bidders if they won't back me up and forbid someone violating the terms of my ad?  I see the section that says countries I don't ship to.   In addition to putting "no international sales", must I fill that out with every country in the world?????  I've been doing ebay for 17 years and have over 1000 feedback.  I haven't had a negative in years, till now.