Angel Tuning and Celtic Tuning do a mobile service, Red Dot are in Watford and you'd have to go to them. Any of those 3 should be able to reign in the turbo pressure for you. Those 3 firms know their stuff when it comes to Alfa engines so give them a bell and talk it over with them, they're the experts and they'll be able to tell you if it's been chipped or mapped. If it's been mapped they'll be able to read the data from the ECU and tell you who did it, when it was done and be able to fine-tune that spike out of the turbo.