As you can see, I've made couple of different design concepts as suggestions for your new logo: ...few pro-looking designs, with greater branding potential, where logo icon can be detached as memorable/recognizable stand alone mark (#127, #128, #129, #130, #134), ...one version with less formal approach (#131), ...and one abstract design, that has this eye catching optical illusion, of Sun trying to inflate from within the square shape of the logo icon (#135, #136),...I don't speak Turkish, but I've googled it and it turns out "sönmez" means "inextinguishable", so the abstract Sun was very nice branding approach, when initials ("S", "G") are not involved.
Hope you'll like some of these, and feel free to suggest improvements if felt needed! Thank you!