Mango Money A vendor returned over $100 to my mando card on April 24th 2018 yet Mango will not apply it to my account. Nationwide

I purchased an item with my Mango Money card and returned the item.  The vendor refunded my money to my Mango qccount almost a month ago and yet they Mango Money will not return it to my account.  Multiple customer service reps have agreed that I should have it in my account and have "escalated" my issue on multiple occasions.  This has gone on for two weeks and everytime I was told it would be resolved in 24-48 hours.  I sent an email to the email address that I was given by a support rep during a call during the day.  They would still not "transfer me to a surpervisor."  Soon I will need to report this to the authorities as theft.  They refuse to refund the money even after admitting that they have received it.