A growing number of sectors are delivering customer services powered by artificial intelligence (AI) instead of humans, with evidence indicating labor cost reduction and efficiency improvement. However, it would be worthwhile to examine the extent to which consumers are satisfied with AI service agents. In two studies based on an analysis of 17,673 Weibo data (Study 1) and 33 interviews (Study 2), we constructed a pair of theoretical models of consumer attitudes toward AI services: a sentiment model and an evaluation model. The results from Weibo data analysis showed that consumers display a stronger negative attitude toward AI customer service than toward their human counterparts. Complaints regarding AI customer service is mainly about its poor problem-solving ability, while untimely response and lack of human touch also dissatisfy customers. Whether consumers offer positive feedback mainly depends on voice traits and service attitudes. The results from the interviews confirm an overall negative attitude of consumers toward AI customer service. Consumers also recognize AI customer service agents as human like and social interaction stress relieving. Taken together, these findings reveal Chinese customers' attitudes toward AI service solutions and provide concrete suggestions for the development and upgrade of AI customer services.