When u got a high ping is because of the country, if the servers ar from ur country and ur pretty sure of that then the issue of the ping can come from ur internet speed, something maybe is eating ur connection, u can check it if u know ur internet speed (supose one) and checking if the download speed (when u download a file) is same as InternetConnection/8 , if u hav 2000kbps internet connection (2Mbps), ur download speed should be 250kbps. (Strongly recomend u download a file from good servers, maybe from ur MAIL a 10mb file, recommend YAHOO MAIL and GMAIL.)
If u check and u hav a normal internet speed , normal download speed, so u can give the fault to ur ISP, sometimes ISP get bad ways to get information or simply use a firewall that makes more ping, so wonder, if ur ISP delay some sec or secs checking all pages/packets that pass throught him, so they make u ping as hell. All about ur ISP really depends about lot of things, but maybe u trully can think on change ISP :/
If any other question just ask :P