There are different societes providing certified auditor programmes, such as ASQ http://www.asq.org/, or IRCA http://www.irca.org/. But the course / training fee is over US$1,200, which is quite expensive. 

Now, you can get "Certified Quality Auditor" in a cheaper way, TAKE a online training course in WITS. You can get a valuable training material with sample Exam questions. You can also send your question to WITS consultation team, our professionals will give you a reply in a short time. 

What's benefit for getting a Certified Quality Auditor (CQA)? From ASQ, you can find that the Certified Quality Auditor is a professional who understands the standards and principles of auditing and the auditing techniques of examining, questioning, evaluating and reporting to determine a quality system’s adequacy and deficiencies. The Certified Quality Auditor analyzes all elements of a quality system and judges its degree of adherence to the criteria of industrial management and quality evaluation and control systems.