Pocket calling It calls the last person called, by itself, while in the pocket - even though it is a flip phone.

Suggest you should free up space on phone. Download Samsung kies (software) to your pc. Back up all important info and reset phone. Also, go to play store and download du booster to your phone and run it. You should have phone working absolutely perfectly.
if not, contact your network provider and enact warrenty on the unit for servicing/repair.

If the problem is that you are making phone calls while it's in your pocket, then go to Settings, Security, and choose either slide or pattern. I highly recommend pattern, because while in your pocket, it can still unlock your phone by just sliding the display with anything.

http://handheld.softpedia.com/get/System-Utilities/Call-Block-Pocket-PC-23561.shtml

visit www.mobiletopsoft.com/devices/spec-o2-xda-iis.html

ENV3 right? two options: option 1:go to settings and tool from the main menu (flipped open and pressed ok) Go to 6: Phone settings. Click security. Type in the last four digits of your cellphone #. Go to 4: Lock phone now. To unlock it: type the last four digits again. If you want to lock it on power up. Go to 3: Phone Lock on that same menu

2nd option: Click over on the keypad surrounding the ok button. Key guard will have a picture of a lock. Click OK on key gaurd. Go to 3: Unlock options. Go to press once or press twice. Then it will unlikely to dial numbers in your pocket. Go to 2: Keygaurd Timer. Set it for 7 seconds. Then, click cancel. Go to 1: Lock Now on the same menu for instance results.

under settings./calls ,scroll to bottom of page.answer on /off tab set to OFF you can use phone as normal then

alright go to the menu then press 9 and 6 two times from the internal keypad it will ask for the unlock code now unless you have read the manual (who does) you dont know that its the last four digits of your phone number(if the phone has service which i assume it does) and press 4 to lock the phone. Now from any menu (interior and exterior) the phone can do nothing but call your ice contacts (who i suggest setting to the people you call the most to avoid having to unlock then relock the phone every time you need to call them) unless you put in the last four digits of your phone number (this code can be changed from the same menu you press 9 6 6 to get to) Glad i could help

On the left side of the phone are two button: A rocker button and a push button. With the flip CLOSED, push the rocker button down. you will see Style:Silent. Push the other button until Style:Loud comes up. Push the rocker button down again to exit the function. Open the Flip and use the rocker button to set the Ringer volume. You can set the ringer volume however you want for each style. My phone swiches by itself constantly when I put it in my jeans pocket, very annoying.

just turn off the bluetooth of your phone

Did you watch the calls happen right in front of your eyes or did you find missed calls on the phones it called? If you weren't watching the phone as it happened, you may just have the keypad unlocked, in which case the keys may be getting pressed while pressure is being put on it in a bag or a pocket.