Google Nexus 4 video problems

[Zaynoon Suna]

hello i just bought nexus 4 two months ago , everything seems to work fine except for the video recording , its really bad , i keep hearing a clicking sound and the auto focus doesn't stop on the playback videos , also it keeps recording the "cellphone radio buzz" noise on videos !! its really horrible

can anyone help
is my device defected ??
thanks