Belize’s local ISP provider, Belize Telecommunications Limited (BTL), blocks internet use of SKYPE and other VoIP applications.
Their reason for blocking is of course to force you to use their services, thereby increasing their revenues.
The fastest way around this is to get a VPN. It’s a basic service that creates a direct tunnel to the service giving the appearance that its not originating from Belize. The most reliable so far has been www.strongvpn.com
International telephone rates for Belize can be found at http://www.belizetelemedia.net/New-International-Rates/rates-sheet.pdf