Try corporate complaint Dept. Should be able to find on the web.
The McDonald's app has a section to file a complaint with whatever location you choose. It also has a "contact us" section you can use to find the appropriate number to call. I highly recommend you use the app, as it is well built, and seems to have exactly what you are asking for.
This locations always seem to have issues with the management. There's a phone number & email address listed on the door for you to contact the owners. Also going to Mcdonald's website and contacting them seems to get the owners to contact you. Contacting them on Twitter and letting them know what location you are having trouble with also helps.
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