Hi Labman,
The old Tedas link does work. I use it regularly and checked a bill on line yesterday. The abone number must be 11 digits so, if yours isn't, just add enough zeros in front of your number to make it up to 11.
http://hizmetler.tedas.gov.tr/TedasI...boneBorcu.aspx
You will find that Muğla doesn't appear in the drop down list. That doesn't matter, just put the other info in.