chapter heading text in words and figures

Please I wish to achieve a replica of exactly the result obtained with this code below except that I want the chapter one heading Instead of 1. when I used the following code `

usepackage{fmtcount}
renewcommand{thechapter}{Numberstring{chapter}}

it worked, but it disfigured my table of contents and I started seeing some numbering like one.1, three. 4 and so on. Is there any way I can maintain my figure numbering in the table of contents whilst also changing the chapter headings in the body of the document to text? Any assistance will be appreciated

documentclass[a4paper,12pt]{report}
usepackage[margin=1in, left=3.5cm, top=2.5cm, right=2.5cm, bottom=2.5cm]{geometry}
usepackage{graphicx}
usepackage{amsmath}
usepackage{lipsum}
usepackage[titletoc]{appendix}
usepackage [T1]{fontenc}
usepackage{titletoc}
titleformat{chapter}[display]
{normalfontLargebfseriescentering}{centeringchaptertitlename thechapter}{0pt}{Large}
titlespacing*{chapter}
{0pt}{-60pt}{10pt}
begin{document}
begin{spacing}{1}
tableofcontents
end{spacing}
addcontentsline{toc}{chapter}{listtablename}
listoftables
cleardoublepage
chapter{Introduction}
section{Background of Study}
lipsum[1-2]

chapter{literature}
section{Empirical Literature}
lipsum[1-2]

end{document}