This is not an answer as there are some other very necessary facts not supplied. However, as a starting point, when you opened your checking account, you should have received some paperwork including disclosures. Those disclosures should be a good starting point.
If that does not work, try calling their customer service department and if it is a mega-bank, try asking for the supervisor. Ask for the fedex tracking information. If you are still unsatisfied and still have not received your money, then you should consider seeking local legal counsel that is familiar with demand deposit accounts and banking regulations.
Lucas J. Nodine is a licensed attorney in the State of Kansas. This answer should not be considered legal advice, but simply used as a starting point for review with your attorney. Understand that no attorney-client relationship has been formed. In other words, you need to contact an attorney if you want legal advice on which you can rely in court. They will conduct a formal interview and review and then they can provide you legal advice.