The thrust of this study is to unveil how effective management of customers could be used as a tool for organisational performance. This study was motivated by the desire to address the problem of loss of customers and subsequent failure by service organisations as a result of poor handling of customers. This loss of goodwill works hardship on business performance. The study thus seeks to find out the extent to which human elements such as bad manner of approach, failure to address customers' complaints by employees reduce customer base, and to determine the relationship between customer base and organisational performance. Data generated from 240 respondents from commercial banks in Warri and Effurun metropolis of Delta State, Nigeria, were analysed using Chi-square to test the hypotheses, and ANOVA to ascertain the variances in response among the five banks, the result indicates that human element such as bad manner of approach, and failure to address customers' complaints by employees reduce customer base and reduction in customer base leads to poor performance. This study recommends that power should be allowed to shift from the organisation to the customers, i.e. organisations should be customer-centric, with employees professionally equipped for the job. Finally, the quality of services to the customer should be at its best. The above findings gave credence to the following conclusions; Human elements such as arrogance, unconcern attitude, unfriendly manner of approach, and facial expression and failures to address customers' complains by the organisation should be discouraged in order for business organisations to perform optimally.