Have been a customer for 30 years, but ending that...

Have been a customer for 30 years, but ending that now. Just deposited a large check that I really needed; it has cleared the account it came from, and they will not release the funds to me. This is going to put me in a major bind, and it is my money! They told me the Fort Mill, SC branch could lift it, but they will not. Taking all 5 of my accounts elsewhere!