Watch out for ridiculous Clause in Tempest Car Hire Rental Agreement

I was charged a R50 per day surcharge on my car rental in December by Tempest because my additional driver had a Code 10 licence! I rented a C-group vehicle for which you only require a Code B licence. It is completely illogical to put a surcharge on the daily rental if a driver is "over-qualified" to drive the vehicle! I booked through Discovery and there was no such clause in the rental agreement. On acceptance of the vehicle it was printed amongst other conditions in small print and not pointed out to the me. I should have read the small print yes, but ridiculous clauses like that should be brought to the renter's attention.