Deceptive trade practices, FDCPA, and state UDAP claims.
Hawaii courts apply both the U.S. Constitution and the Hawaii Constitution to consumer protection claims. When state protections are broader than federal ones, Hawaii judges follow the state rule. When they are equal or narrower, federal precedent controls under the Supremacy Clause.
Federal cases governing consumer protection include controlling U.S. Supreme Court decisions and binding precedent from the federal circuit covering Hawaii. Civil remedies most often proceed under 42 U.S.C. § 1983, with defenses including qualified immunity.
Legal information, not legal advice. For advice on your situation, consult a licensed attorney in Hawaii.