Dont discount the role played by your employer in all this Paul as they operate the PAYE system on behalf of HMRC and should have changed the codes of all their employees to reflect budget changes in which case there would be no overpayment and also consider that sometimes people are underpaid and that is more of a shock to the system !
Having said that the PAYE system is a bit archaic and been more or less the same for decades and often things cannot be put right until the end of the tax year when actual total income and tax paid is known , if you then throw into the mix people who change employers mid year ,have company cars, get made redundant etc it can all become complicated, especially if employers don't issue P45s etc.
I am not blaming employers who can make mistakes like everyone else, and after all are unpaid tax collectors on behalf of the government, and HMRC just putting right your tax going back to 2008/09 also indicates a failure on their part.
You may be interested to know that HMRC is currently undergoing a digital revolution and the old archaic system is on its way out to be replaced by a " real time " system which will allow you to look at your tax account online, it is being piloted in certain areas of the UK currently and feedback from members of the public is very favourable, it will then be rolled out across the UK.
I would still go to the RR/Bentley showroom as they are superb cars and well worth a look, but I guess your refund will only pay the bus fare !
Robs Pictures at :Robs Car Gallery
click below to access nano websitePlanning is an unnatural process, much better to just get on with things, that way failure comes as a complete surprise instead of being preceeded by a period of worry and doubt