I think the ONLY provider is Turk Telecon. Their offices are on the road opposite Kipa going toward the sea. They are on the right hand side. You will need to have residency to get a line, you'll need your own phone and probably an electrician to finish the installation. It helps if you can give them the tel number of a near neighbour - so they know where you are on their system!
About a week after you get your home line you can apply for ADSL internet, when we had ours, 3 years ago, they provided the wifi router, not sure what the package costs are now as we use a dongle since moving. We also now live near the Sevi.