maybe your provider will have a kind heart.
about 10 years ago i was at the beach near pensacola florida and was using my cell phone on the balcony overlooking the gulf.
evidently i was hitting a tower on an oil rig or something in international waters instead of going through the concrete 10 story structure i was in.
that week i was on the phone for close to 15 hours, and almost every minute of it rang up as an international call at $4/minute.
however, a call to my provider straightened it all out.