Localphone can call 1800 numbers for free. You may want to check your call logs to see if the calls are being sent in the correct format. I believe they must include the leading 1. In the past I have created speed dials to test setups.
For instance if localphone is SP1 I would put the following string in speed dial slot 1.
SP1(18008336354)
Now I can send 18008336354 directly to service provider 1 by dialing the speed dial. This will bypass changes made by digit maps that might be causing an error. If the speed dial works but dialing the number outright does not you know there may be an issue in a digit map or a outbound callroute. If the speed dial doesn't work there is probably an issue with the general setup.