First, the Bulgars most likely were not “Proto-Turkic” people (though they might indeed have had partial Hunnic descent). The modern theories suggest mostly Iranic origins.
Second, the Bulgarians are not Bulgars. The ethnogenesis of the Bulgarians was finished more or less by the early 10th c., when the Bulgars and Slavs (and non-Slavicized locals) finally merged into one, the Bulgarians.
Third, the Bulgarians are Slavic and that is an indisputable fact. If you don’t believe me, open any book on Slavistics.
And if I may be so bold, I’ll even quote the father of our Revival, the author of the Istoriya Slavyanobolgarskaya, St. Paisiy of Hilendar: “Out of all the Slavic kin, most glorious were the Bulgarians – they were the first to call themselves tsars, they first had a patriarch, they were the first to be baptized, they held the most land.” I’ll also add that the Bulgarians created the Cyrillic alphabet and spread it to Serbia, Romania and Russia, together with its Slavic Orthodox culture and literature (a Slavic adaptation of the Byzantine one). I can go on and on with quotes f.e. from Likhachov and what he calls “the Bulgarian state/country of Spirit”, about “the first Slavic language of literature” etc.
Now, if you have a personal or national(istic) problem with Bulgaria, or are just trolling – that’s another matter.