A question of thought. The OP is in the UK and I was under the impression that in the UK the phone operators have a very rigorous blacklist system for mobile phones. Therefore, if the OP has contacted the network company telling them the iphone had been stolen, the company would have added the iphones imei to a blacklist which is used by all the UK network operators. Thus, if the thieves are sending messages to his wife, just exactly are they doing this? because they would not be able to use the mobile network because the imei would be flagged and thus prevent the iphone from working. Putting in another sim card would not work because again the iphones imei would be blacklisted and thus prevent the iphone from working. If the thieves are using wifi, surely the messages they send to the OP's wife will be tagged with the IP number of the wifi they are using. And this poses another question, if the iphone was reported stolen to the network provider, the phone number would not work either so again how are they able to message his wife? If they are using apps such as whatsapp, surely the thieves must be using wifi which is easily traceable by the police.