Cfrgtkky

I have two issues in my Table of Contents.

1. Bibliography appearing twice in Table of Contents


2. Title of Table of Content has improper spacing
   
   

Latex below:
1. For Bibliography

phantomsection 

addcontentsline{toc}{chapter}{Bibliography} 

bibliographystyle{unsrtnat} 

bibliography{references}

begin{thebibliography}{9}



bibitem{SVIT} Matek, Tadej and Timej Zebec, Svit. (2016). GitHub open source project recommendation system. 



bibitem{Yun}

Zhang, Yun and Lo, David and Kochhar, Pavneet Singh and Xia, Xin and Li, Quanlai and Sun, Jianling. (2017). Detecting similar repositories on GitHub. 



bibitem{Surbhi}

Sharma, Surbhi and Mahajan, Anuj. (2017). A Collaborative Filtering Recommender System for Github. International Journal of Emerging Technologies in Engineering Research (IJETER). 



end{thebibliography} 

2. I have used a chapter setting to automatically center all chapters. But for some reason Table of Contents seems spaced out. No other chapter or section has that error.

MWE

usepackage[pagestyles]{titlesec}



titleformat{chapter}[display]

   {normalfonthugebfseriescentering}{centeringchaptertitlename thechapter}{20pt}{Huge}

titlespacing*{chapter}

   {0pt}{5pt}{4pt}



newpagestyle{mystyle}{sethead{}{}{}setfoot{}{thepage}{}}

pagestyle{mystyle} 

You mix 2 different ways to produce a bibliography.

Either use

bibliographystyle{unsrtnat} 

bibliography{references}

or

begin{thebibliography}{9}



bibitem{SVIT} Matek, Tadej and Timej Zebec, Svit. (2016). GitHub open source project recommendation system. 



bibitem{Yun}

Zhang, Yun and Lo, David and Kochhar, Pavneet Singh and Xia, Xin and Li, Quanlai and Sun, Jianling. (2017). Detecting similar repositories on GitHub. 



bibitem{Surbhi}

Sharma, Surbhi and Mahajan, Anuj. (2017). A Collaborative Filtering Recommender System for Github. International Journal of Emerging Technologies in Engineering Research (IJETER). 



end{thebibliography} 

but not both (unless you want two bibliographies)