Europcar is terrible after returning of car

started of perfect rented a car just fine. went to Hatfield branch on day of collection payed the deposit en off i went . 10 days later i returned car and they found a scratch on front bumper , fair enough.. 20 days later they let me know i have to pay the extra cost for the damages , also , fair enough. this morning i took a day off work to go pay the extra costs i owe and was promptly told that i cant pay at the Hatfield branch in person ... now explain to me why they can take my deposit at the branch but not the extras at the same branch... so now I'm in a situation where I'm sitting with the cash to pay them but they don't want to accept it at Hatfield branch ...***