Many customers were unable to access the site following a maintenance period and make payments for their journeys over the Dartford Crossing.
As the deadline for payment approached, drivers became concerned about potential fines.
News Shopper readers on Facebook dubbed the changes as a “rip off”, “scam” and “biggest money pit of time”.
National Highways, the organization responsible for the upkeep of the crossing, issued an apology for the inconvenience caused by the ongoing website issues.
Dart Charge released a statement acknowledging the problems and assuring customers those improvements had been implemented.
A spokesperson for National Highways said: “The @DartCharge websites and customer contact centres are all operating.
“We apologise for the service issues users have faced over the last few days and have implemented service improvements.
“While customers may still experience short delays, the average online wait time is now less than 5 minutes.
“We have further extended payment deadlines to ensure everyone has sufficient time to pay the charge.
“Account holders have until 31 August to update their card details on the website. Non-account holders who use the crossing between 27 July and 14 August have until 15 August to pay the charge.
“We apologise again for the inconvenience, which was due to essential system updates.”
Below is what News Shopper readers have to say about the changes to the Dart Charge system
Samantha Lowe said: “This is another scam, motorists have well over paid for this crossing.
“It’s an ongoing war on vehicle owners.”
Jacqui Osborne said: “What a joke!”
Jen Letchford said: “Check your vehicle list.
“This updated has added every car you’ve previously deleted back on – I had 9 to re-remove today.”
Sharon Read said: “Be careful, went in today to update my details, and had added back 4 vehicles we no longer own, one was duplicated, and another was the reg before we put a private plate on.
“So I could have needed up paying for someone else’s trip!
“There is a feedback form, so went to town, and also said we shouldn’t be paying for it all as has already been paid for.
“Unmanned now, the only bit that is looked after are the escorted vehicles- make them pay for the staff needed to man that if we really have to pay at all.”
Justin Simpson said: “RIP OFF BRITAIN “THIS SHOULD BE FREE.
“Bridge has been paid for over and over again.”
Wil Wilkinson said: “Should be free what a rip off it was, paid for years ago.”
Mark Cookman said: “Hey hang on I thought we we told that when the bridge was paid for it would be Free ?? .. Oh hang on we were told to buy Diesel engines because they were cleaner now and saved fuel.
“Oh hang we are being told to buy Electric cars to save the environment and are cleaner than fossil fuels?”
Mark Stewart said: “In other news Stealth Tax to net millions of pounds more due to ‘exciting changes putting providers first.”
Gina Barker said: “Time it was FREE… Biggest money pit of all time.”
Simon Peers said: “I set a reminder to do this but the website was down all weekend, now it puts me in an endless queue that times out.
“It is a joke, especially as this crossing should be paying us for all the time we waste queueing.
Roisin O’keefe said: “I would happily pay 50p per trip just to keep the maintenance up on this bridge and tunnel.”