Mystery Auditor

I am looking to have a mystery auditor visit my retail store to audit our customer service operations. The audit should include observations and assessments of the sales associates' customer service skills and knowledge. Specifically, the auditor should focus on how helpful and friendly they are to customers, their ability to answer questions accurately and make product recommendations, and their ability to resolve customer inquiries and complaints. The auditor should conduct the audit within one week. Any feedback provided should be detailed and comprehensive so that I can implement it quickly and effectively.