Ustomers patronization to Islamic Banks

My reasearch question is Why would customers patronize or prefer Islamic banks?and the answer is because of the customer services and the products. so my theoretical framework is as follows:
dependent variable:customer patronization
independent variables: services and products
i want one page introducing the topic
then A 5 comprehensive literature review and research questions


a. Research Design

b. Measures and Scales

c. Questionnaire Design

d. Data Collection Methods

e. Sampling Design
and the end recommendations and conclusion