Problem with in-text citation numbering and bibliography reference repetitions

I am using reference manager 11 and for some reason when I use the same reference twice or more in the document it gives it a different number every time. For example, if I cite Atkin on pg. 1 it gives it [1] (according to my style) and if i site it again later it would give it another number [3] or whatever, depending on its order. Shouldn’t the same citations get the same number? In addition, when I generate a bibliography, the references repeat themselves as many times as I cited them. 

What I need to have is the references cited in order of citing but with each reference having its unique number and no repetitions in the bibliography.

Does anyone know how to fix this?