IBERIABANK Bank Account Or Service Complaint

IBERIABANK Bank account or service department,

(CD) Certificate of deposit Account opening, closing, or management Arkansas

I closed out a certificate of deposit at IberiaBank. They mailed me a check for $30000.00 and did not send it by certified mail. They sent it by first class mail. The check never arrived. It has been 30 days. They do not want to issue another check for 90 days. I do not believe they will ever issue a new check. Why am I supposed to believe someone who uses the excuse, " The check is in the mail! "?