Do not make a scene or hold up other customers in line.
When confronted with a problem in a retail establishment ask for the Manager on Duty (MOD) to explain your complaint. When first approached by the manager ask for his calling card before you enter your complain. If you have a calling card offer one to the manager.
If after expressing your complaint and review by the manager and you do not receive what you consider adequate resolution of your problem, request the name, address, and telephone number of the District Manager (DM) for the Store.
You can then notify the DM by telephone or other means.
If you follow the above suggestion in a civil manner, 95% of the time your problem will be corrected.
If you still feel your complaint was not adressed properly. Look up the CEO of the establishment and forward him an E-mail or letter.