The objective of this research is to contribute to applied linguistic theory and to provide insights into the world of workplace telephone conversation. The study examines the structure of telephone call centre dialogues. The interaction entails a wide range of customer service inquiries and problem-solving objectives, in which the Customer Service Representative (CSR) responds to inquiries while attempting to maintain a positive interpersonal interaction with the customer. We chose and evaluated a representative sample of calls having complex negotiation structure or even a communication breakdown. We describe how the conversation progresses and how one response leads to the next in problematic calls with faulty exchange structure (Halliday, 1985, 1994; Ventola, 1987). The data consist of audio recordings of Filipino Customer Service Representatives interacting with English-speaking American customers during commercial customer-service phone calls. 20 representative calls with complex negotiation structure were chosen from approximately 2,000 calls. We used Systemic Functional Linguistics (SFL), which provides a comprehensive theoretical framework that may be used as an effective analytical tool, to investigate the semantics in terms of logical relations of the exchange structure in the transcripts.