Europcar incapable of advising hirer of toll infringement timeously

As a visitor to the UK I hired a car from Europcar. All went well and I was happy with the service. A few weeks after I had returned to South Africa I received by post advice that I had 2 toll transgressions of 2 x £2.50. Subsequently I received a penalty Charge Notice from Dart Charge x 2. In each and every case I received the post after the due date for payment. I am now expected to pay 2 x Euro 129 for Dart Charge and 2 x £80 to Europcar (Admin Fees)

I strongly advise any overseas car hirers to avoid Europcar as they could easily suffer a similar fate. I suggest to Europcar that they advise any hire customers of any fines by email as soon as an issue arises.