My iphone hangs up after 2 hours?

It tells me i have gone over my minutes at exactly 2 hours, i have unlimited calls. Is it safe to ring the person back?

Yes it happened to my blackberry yes you are safe i think its just a phone limit not service

Ring yes
Wring no

Many networks have a built in cut out that varies from one network to another.
This protects your allowance, in some case a call is NOT DISCONNECTED BY THE RECIPIENT.
An example of this is a call when you have to select an option and it repeats.

If you accidentally dial a number and it connects, and you were NOT aware you remain connected, the network ends the call after 2 hours but those who find out the hard way, 1 hour would have been better if landed with a huge bill, but 1 hour on an actual call would affect many people,

I don't think it can be increased on a individual basis but does come as a surprise as there is NO "And now some messages from our sponsors"