Report the bad behavior to company executives. It's possible, even likely, that higher levels of management aren't aware of the extent of behavior at local branches and stores. Find the address of the corporate headquarters on the company website or in promotional materials. Write a letter describing the behavior, address it to Executive Customer Service and send it by certified mail.
Report the incidents to a consumer advocacy group. These organizations can usually escalate disputes and concerns more quickly than the average consumer. For example, organizations like the Better Business Bureau can field complaints regarding local and national businesses. Furnish the organization with contracts, agreements, copies of emails, photos and other evidence regarding the quality of products and services.
Alert applicable government agencies to the problem. Depending on the business in question, there may be a state or federal watchdog that regulates the profession and fields complaints. Consumers can file complaints about lawyers, certified public accountants and public utility companies with state agencies in some places. The Federal Trade Commission fields complaints regarding telecommunication companies and financial service companies on a national level. As you would with consumer advocacy organizations, furnish any evidence you have that supports your concerns.
Craft an honest review of the company and post it on consumer review websites, rating sites and social media. Although it's not a traditional method to get recourse, you can alert other consumers to bad behavior and perhaps save them some grief. Enough negative reviews can severely curtail new business opportunities. For this reason, many businesses will quickly follow up on your review to try to make good.