A rail operator has apologised to a Midland MP after leaving him stranded in Oxford as he tried to get home.
Peter Luff (Con Mid Worcestershire) uses First Great Western's trains to travel between his Worcester home and London.
But twice in the past two months, services have stopped in Oxford - with passengers told the train would go no further.
It meant the MP, returning from a week at work in the House of Commons, was late for appointments with constituents.
And when the service does go the distance, Mr Luff said it was frequently delayed.
Now he has received an apology from Alison Forster, managing director of First Great Western, who admitted services "have been delayed and disrupted far too often" and promised they would improve.
The MP was prompted to write after FirstGroup, the company responsible for the First Great Western network, had its franchise renewed just before the New Year.
First Great Western runs trains from Hereford through Worcestershire, stopping at Worcester, Pershore and Eve-sham, through Oxford, Reading and Slough and finishing at London Paddington.
First Great Western will be merged with the Wessex franchise, which links Gloucestershire with Devon and Cornwall, to create a new network called Greater Western, operated by FirstGroup.
In her letter, Ms Forster said: "I can fully appreciate your frustration with continuing delays. I assure you that we are committed to reducing delays whenever possible.
"As I am sure you will appreciate, not all delays are caused by reasons within our control. However, you are our customer and I can understand why you feel very let down."
She added: "We are very aware of the strength of feeling of passengers on the Cotswolds line, and I do know that services have been delayed and disrupted far too often.
"There is no one single factor that we can say has caused the delays and I can only hope to reassure you that we have no desire to run an unreliable service."
But one of the problems the operator faced was that part of the route had only a single line of track - making it impossible for trains to overtake each other.
It meant if one train was delayed, everything behind it was likely to be delayed too, Ms Forster said.
Mr Luff said: "I have a lot of sympathy with many of the things Ms Forster says."
But he added: "The way First Great Western has dealt with problems not of their making has often made matters worse. Terminating services at Oxford is just not acceptable.
"Alison Forster also rightly emphasises that the long single line sections between Worcester and Oxford compound any problems.
"All the line's MPs must lobby the Government and Network Rail for major infrastructure improvements."
Mr Luff said: "First Great Western has not provided the service we have a right to expect, but now they are to be our train company for at least another seven years I am determined to work with them to deliver a better service by ensuring that the Government and Network Rail listens more carefully to our case."