android missed call notifications not going

I have a *Samsung Galaxy S6012.* Long time back (I do not remember when) I've got a call. Even though I answered that call, it was put as missed call. Since then it shows a missed call alert in my phone. First I removed that particular number from the list. Still the same alert was there. Then I removed the entire log history – still the same missed call alert. I have restarted the device many times but all my work went in vain. **NOTE** By "missed call alert" I mean a numeric ① being displayed on top of the phone icon: This is the phone I have The phone icon is at the bottom left side.If any missed calls then I get a number(like 1,2) at the top like this