I don't rent vehicles very often, but the last two times I have hired a vehicle there have been unexpected refueling costs appearing on the invoices. The rentals were with different car hire companies.
I returned the vehicle with a full tank (filled at the airports service station) and then noticed that the amount charged included a refueling cost - the first time for about R100 and this last time for about R25.
In both cases I sent a query to the companies, and the extra charge was reversed.
Has anyone else noticed this before?