I have a Galaxy Ace and on a $20/mo. simple tab. Today I received a bill for 2 local calls totalling 150 minutes (= monthly bill of $103). The charges incurred because the phone did not hang up after the other person hung up. The keypad screen flips back to the main screen but the phone is still on the call. Do I have to press the End Call button. Can I get out of having to pay the charges for the calls? Aren't local calls supposed to be free?