Phone Hertz on their UK contact number 0207 0260 077, where customer services staff take enquiries regarding car rentals.
There is also the option of visiting Hertz’s contact form to enquire about a longer term rental at this web address: http://www.hertz28.co.uk/contact.aspx

Hertz is a car rental company, which offers both short and long term leases on vehicles. Mindful of the various customer care needs renters have, Hertz offers opportunities for vehicular rent to buy as well as an impressive selection of cars.