vision prepaid Runaround concerning refund check internet

A very large deposit was made to my vision prepaid direct deposit account. I was unable to access more than 500 dollars a day in cash. My only recourse was to close my account and receive my funds in the form of a refund check. I was informed that it would take 3-4 weeks to receive. After 31/2 weeks I called and was told the check had already been mailed. After 4 weeks....no check. I called again and was told there was no check mailed and my account was under review because it was so large and they didn't know when they could answer any questions about my account because there were others in line ahead of me.  I feel they are using my funds to earn money while denying me access to my own money even more than a month after my account has closed. Can I sue for damages since I lost an opportunity to complete an investment deal due to lack of funds?  Val, riverside calif.