This is weird!!

Lately there is unknown or safed number keep calling me..y cant they juz call back..i call back they dun wanna pick up..wat lar..then miss call for wat???wat is their problem???or juz sms to say lar hu r u ...haih yor..stop calling lar...very annoying lar..or if it is prank call juz cut it out..if it is for something important pls call back or sms..thank u...