First Group have let me know they are sorry that overrunning engineering works prevented them from running the promised services on Saturday. They adapted the services when they found out they were not getting rail access to Paddington back at the specified time early on Saturday. They are also willing to compensate people for loss where passengers were not able to undertake the journey they had paid for. As the train operators explains, they can run a sensible timetable adapted for engineering works, but they do need to be able to rely on the start and end times for these works, and need proper notification of any changes to plans. There is now to be an enquiry into these difficulties caused by Network Rail. Passengers can contact if they have points they wish to make.