We pride ourselves on being a "customer-based business," and we are displeased when any employee provides poor customer service.
We have received several reports of your disinterest in assisting our customers. Over the past few weeks, many customers have specifically stated that you spoke to them disrespectfully. We have also received complaints that you completely ignored some customers.
This type of conduct will not be tolerated at [company name]. If this behavior is not rectified immediately, then we will take disciplinary action – up to and including termination. I am confident that this situation will be resolved without further action from the company.