Metro PCS Charged for service not requested- and refused refund or credit Florida Nationwide

I opened an account with two phone lines, and at the time requested insurance on both lines. At a later time, I called to cancel the insurance, and was told that one of the lines did not have insurance. I was being charged for a music service that I did not ask for and never used. 

I called customer service to speak with someone about a refund or credit for this, I was told that they cannot do that due to the service being a request/add on. When I asked to speak to a supervisor, I was told that they do not take calls. 

So result, I was charged for something I never asked for, and they will not credit for this due to the fact it's a request/add on, and no supervisor to speak with.