Credit on account

I received a credit on a mobile account that I never wanted and was being charged for.  After numerous calls from October through last week, I received partial credit back to my card.  There was an outstanding credit balance that I requested be returned to my card and when the billing cycle ended 11/19 the credit was reversed and the account said paid in full.  There was never a balance because I never set up mobile service, there was nothing to pay.   I’m out $152 that I want back.  Calling is pointless and I will be filing a consumer complaint to every agency that I can if this cannot be resolved.  It’s not ok to do this.