Neighboring Business Refuses To Stop Sending Their Customers To Our Bathroom. Help!

(This is my first time posting on here so if I’m missing any important info let me know!)

Important info: Orange County California. The business in question serves alcohol and food such as pastries and sandwiches.

For years now a neighboring Cafe has been sending their customers to use our bathroom since they don’t have one available for theirs. We have called dozens of times asking them to stop but they deny they do it in the first place. Their customers come with their coffee cups in hand and ask to use our bathroom with no intention of buying something. They will openly admit they were sent by the coffee shop and we have had employees go in out of uniform and ask, they are absolutely sending people to our bathroom. It puts us in a difficult spot having to turn half of the people who walk through our door away and make them upset when they can’t use our bathroom. There are public bathrooms, but not very close by.

Any advice? Should I report them to the city? If so, how? Thank you!!!