This case study provides a comprehensive analysis of consumer behavior within Telstra, a prominent technology and telecommunications company in Australia. It explores the social, environmental, and individual factors influencing consumer decision-making and brand switching. The study delves into theories such as the reasoned theory, motivation need theory, and Blackwell consumer behavior theory to understand customer attitudes. Environmental factors including economic, political, and technological influences are examined, along with individual factors like service quality and brand value. The analysis incorporates survey results indicating Telstra's popularity and customer loyalty. Recommendations are made for Telstra to focus on technological improvements, social media engagement, and targeted messaging to enhance customer attraction and retention, ultimately aiming for sustainable marketing solutions that benefit both the company and its customers. The report concludes that Telstra possesses a good market share in the telecom industry of Australia and only needs to focus on the determinant of the consumer buying behavior and work on the findings.