A Wink & A Smile

Back in Christmas Time of Dec 2017, this business had a booth in a local event and was advertising to have a free Dental Check/Cleaning for Free, without using the Insurance. My son, *** (11 years at the time) did put his information and did schedule a visit to the practice on Jan 02, 2018.
As I am working, my wife did take him to the appointment, and once there, as usual she had to sign some paperwork, and she double check that this is a free service and if we do like it we might switch dentist in the future. The lady was very affirmative and helpful. after that, we started receiving a bill from this practice, and we were told that those bill are denied by our insurance because the service is only covered once a year. I did try many time to reach to them and explain to them that we did share the information with them that we do already have a family dentist that we go to regularly, but the customer representative did not take those fact into account. after months of treating and Collection letters start to show up, I was forced to pay the $208.00 on Mar 21, 2019. Not just that, but also now they are sending a bill for late payment of $35.00.
Why in the word this business do advertise a free cleaning and then take the customer and provide an array of services and bill his insurance and then force the customer to pay the remaining.