If you go into your self serve, look under your Add-Ons and make sure the free Pay-Per-Use Intl Long Distance add-on is there.  If it is not, add it and then you will be able to call long distance numbers.

Note that long distance calling is not free.  you will be charged pay per use long distance rates or if you have a long distance add-on you may may have preferred long distance rates or long distance minutes to specific countries.