Sections 1321.01 to 1321.19, inclusive, of the Revised Code may be modified, amended, or repealed so as to effect a cancellation or alteration of any license or right of a licensee, provided that such cancellation or alteration shall not impair or affect the obligation of any pre-existing contract between any licensee and any borrower, nor the right of the licensee to collect principal, interest, and charges as set forth in said obligation.