In my Samsung Galaxy i5801 after I disconnect the call I used to get a call summary from my carrier. This hasn't worked for some time. I contacted customer care and they say some settings in the phone are changed and probably they are right because when I use the sim on any other phone, it shows the call summary. Does anyone know how to fix this?
I would try a factory reset via
Settings -> Privacy -> Factory data reset. This will wipe your phone, so make sure to do a back up first if you need to (you can search this site for backup methods).
No need to factory reset your phone. Simply turn off mobile tracker, it will work.