Ashburn Endodontics

I was over charged for service, service date was Oct 4th, 2019, *** paid them on October 31st, 2019. I called once and they told me to call the insurance company, they "Claimed" they were never paid, I called and left another messages in November telling them that I was due a refund how can we get this processed,. its been a whole week they never called me back, I have emailed them the copy of my statement and they copy of my receipt to show I am do a refund. I have received no phone call and no response to my email. I don't care how small a refund to a customer is, we want it back, stop holding on to money that does not belong to you. I am due a refund of $10.00.