They Resolved the Issue
I saved a receipt from my dentist. They charged me, then delayed the procedure I paid for. When I asked for a refund, they changed my entire bill and told me that I owed them another $300, despite the fact that all they did was clean my teeth and take my x-rays. I submitted both copies of the invoices to my dental insurance company and told them what happened.
Three weeks later, the insurance company resolved the issue with the dentist and I got a refund. Despite the dentist attempting to defraud me, they still regularly call me asking me to come back in.
Story credit: Reddit / 1and2halvespeople