How to track down a missing international payment

I was due to be paid for some work earlier this month and the payment was from a foreign bank account into my account in GBP. The payment was made two weeks ago but never turned up in my account. After numerous phone calls with my bank and a lot of help from the CFO of the company I am working for (thanks Mario) we eventually managed to locate the payment.

The key step in resolving it was to get the paying bank to produce an "MT103" - this is a SWIFT payment confirmation. I was then able to send this to my bank and they were then able to use this to track down what happened. It turned out that it had been somehow credited to the wrong account but with the MT103 as proof that it should have gone to my account it was resolved very quickly and the money moved to where it should be.