(a) A creditor who charges or receives legal interest that is greater than the amount authorized by this subtitle is liable to the obligor for an amount that is equal to the greater of:
(1) three times the amount computed by subtracting the amount of legal interest allowed by law from the total amount of interest charged or received; or
(2) $2,000 or 20 percent of the amount of the principal, whichever is less.
(b) This section applies only to a transaction subject to this subtitle.