timing chain or tentioners are going out again,this makes the fifth time 150,000 on 2001 Chevrolet S10

three different macanics have worked on it,, about time chevey pais for this one,, who would I contact for such a request,,

Asked by for the 2001 Chevrolet S10
Has it been dealership mechanics doing the work? what kind of oil change schedule do you keep with the truck ?