Every licensee who lends any sum of money may contract for and receive charges at a rate not exceeding the sum of the following:
(a) Two and one-half percent per month on that part of the unpaid principal balance of any loan up to, including, but not in excess of two hundred twenty-five dollars ($225).
(b) Two percent per month on that portion of the unpaid principal balance in excess of two hundred twenty-five dollars ($225) up to, including, but not in excess of nine hundred dollars ($900).
(c) One and one-half percent per month on that part of the unpaid principal balance in excess of nine hundred dollars ($900) up to, including, but not in excess of one thousand six hundred fifty dollars ($1,650).
(d) One percent per month on any remainder of such unpaid balance in excess of one thousand six hundred fifty dollars ($1,650).
This section does not apply to any loan of a bona fide principal amount of two thousand five hundred dollars ($2,500) or more as determined in accordance with Section 22251.