restarts after every call automatically

My samsung galaxy y, model number gt-s5360l and android version 2.3.6 constantly restart everytime I get a call. It happens right after I hang up the phone. Even if the call last one minute or two hours the same thing occurs. I tired running an antivirus scan but two different type of software did not find any viruses. Can anyone please advice me on what to do about this? I bought the phone approximately eight months ago