Upon institution of proceedings for the collection of a small business loan in default, a bank may charge a collection fee, in addition to court costs, according to the following schedule:

(a) on the first $750 of indebtedness, 15%;

(b) on the excess over $750 of indebtedness, 10%, but in no case shall such collection fee exceed $500.00.

L.1964, c. 162, s. 7.