There have been problems with the post in the past couple of months, I've had a few items take over a week. I made a comment to the Postman about a month ago and he told me the delivery van from Dudley (main sorting office) hadn't turned up 2 days running at our local sorting office. The Post Office should have given a proof of postage receipt and than covers up to £30 if there was no insurance/Special Delivery.
I had similar issues with repairs sent to Johnsons Photopia, the Mamiya/Tamron importers and service agents. First a 17mm Tamron lens that needed a new aperture mechanism, that came back with smearing on the inner surfaces of the lens cells and was unusable due to flare. A few years later they serviced my Mamiya 645S and it came back with the same faults, it went back and they rectified the flash synch but not the other issues, and meanwhile had managed to chip the corner of the pentaprism -internally. Apalling service.
Hang on in a few days it may still arrive.