Over-running engineering works caused widespread delays and cancellations on all services via London Bridge on Monday and Tuesday.
The rail operator has received almost 9,000 claims for compensation for delays on just one day.
A Southeastern train. Library picture
Now Dartford MP Gareth Johnson has met with Southeastern boss Charles Horton and John Macquarrie from the Department for Transport.
He said: "Southeastern received over 8,800 claims for compensation just for Monday's delays.
"I know that sometimes services do not operate as they should, but there is no excuse for poor communication and a level of service that was deplorable.
"Southeastern did not give passengers sufficient information about the level of disruption to allow customers to make the best decisions about their travel plans.
"They conceded during the meeting that they were operating under the wrong information believing that the engineering works would finish earlier.
Southeastern managing director Charles Horton
"Engineering works may be Network Rail's responsibility, but communicating with passengers is very much down to Southeastern.
"Trains in Dartford were being allowed to depart knowing full well they were heading for a log-jam further down the line into London, leaving passengers sat on the line for over an hour. It is simply not an acceptable level of service.
"I would urge all commuters, whose journeys were delayed by more than 30 minutes to make a claim via Southeastern's delay repay scheme."
Southeastern and Network Rail both apologised to passengers.
A Southeastern spokesman said: "Following the disruption we wrote to Network Rail in the strongest possible terms to express our frustration and dissatisfaction about the disruption on behalf of our passengers. They have responded by launching an urgent review, which we'll be taking part in.
"They have also decided to postpone some similar works until they have got to the bottom of the issues that caused these problems."
Mr Johnson also took the opportunity to speak to them about other issues – including stopping any planned reduced services to Longfield and Meopham.
Other areas covered included this year's winter contingency plans, the cost of parking at Ebbsfleet station, faster services to Dartford and having the opportunity for Dartford residents to use the Oyster card.
Dartford MP Gareth Johnson
Mr Johnson added: "I've had enough of poor service and a lack of joined up ticketing for commuters.
"We have a situation where commuters cannot use their Oyster and there is no other scheme on offer from Southeastern at present that can use the technology we know exists to help customers save money and allows them a more joined up service with London. I want to see all of this change.
"One piece of good news came from the meeting and this was that Southeastern and the Department for Transport have agreed with my request not to reduce the services that stop at Longfield and Meopham station."
Along with Gravesham MP Adam Holloway, he campaigned against suggestions from east Kent passengers asking for a reduced service at Meopham and Longfield to improve their journey times.
Mr Holloway said: "Cancelling a two-minute stop each at Longfield and Meopham would surely not be of huge benefit when compared to the disadvantage to others using these two stations."