Huge problems, on mobile plan NEED help ASAP, Have contacted support 8 times already

Hello there is a huge problem on my mobile plan.  

For some reason, there were a bunch of refunds attempted that I did not request.

I did not receive any of the refund money into my account

It is now showing my account balance owed is over due, and the amount of the refunds that I never received.

I now am past due for $387, and I did not even request those refunds, and I never got them

I am basically owing money I have already paid. No one seems to be able to understand or be able to help me.

I need help ASAP, they will close my account if I do not pay .