rentalcarticket.com dollarrentalfine.com $19.90tolls, $90 Admin fees. Internet

Several weeks after returning from USA where we hired a vehicle I recieved a letter saying my credit card would be debited $109.90 for tolls incurred.  I had no prior way of paying these tolls but Dollarrentals or Rentalcarticket has added $90 in admin fees.

These toll fees were all incurred on the same day in the same municipality of Aurora (CO) and as such would have all been paid to the toll company at the same time. But I have been billed for six ($15) Administration fees.  It seems exorbitant to charge such fees particularly when I was given no prior way to pay these tolls. I only received the bill for this some six weeks after the tolls were incurred. Couldn't they have asked for payment of these tolls when I returned the car two weeks after they were incurred? It seems they have negated to allow me to pay the tolls so they can issue me with heavy administration charges and they hope that being from overseas I will consider it to difficult to dispute and just except it.