Pathetic Service From Chevron Managment

I made a complaint about a incident that took place on the 18/12/17 . I notified Chevron I was not happy with the outcome 2 months ago ,while speaking to manager I notified them on email (have the proof) that I wanted the complaint escalated . Since no-one has ever come back to me . Chevron's service has been pathetic No-one stays in contact or even keeps the client updated with feedback I had to constantly phone around and even the managers dont get back to you . They dont follow the complaint procedure even tho they send it to you on email . My compliant was meant to resolved in 3-5 working days . Its been 3 months and yet nothing .