With this link you can inquire your unpaid bills ( Normal Borçlar ) and paid bills ( Tahsilat Görüntüleme ).
http://www.muski.gov.tr/viewpage.php?page_id=31 ) You have to select "Abone No ile" and click "Devam Et" .
2 ) Select "Bölge" ( the area where you live ) from the pull-down menu.
3 ) Enter your "Abone No" ( subscription number ) , this you will find on your bill , 3 rd item from top left and click "Ara".
4 ) If you have an unpaid bill , you can pay it here on line with your credit card I remember. ( As I got our new bill a few hours ago , I Can't see a link for on line payment yet ).