I believe it may have been repaired at Dave Clarke's home in Swindon. He was the Designer of the amp. I say this because everything about Adrian's business is vitrual. There is no office, no factory, no employees and I think no products. But there is a Web Site.
Dave Clarke has of October 2017 sold up and moved on. And at least according to Companies House in the UK is not a Director of the 3rd and soon to be struck off version of Deltec Precision Audio.
Perhaps you bought your equipment from a guy called Andrew Lovely?
After May 2011 when Adrian and Dave broke Company Law to sack me I lost interest in their brand and products.Their only passion in my opinion was greed.
My experience of Dave Clarke's designs much like the Reviewers is not favourable.
Your amp has been stolen so you should at least lodge a complaint with the British Police. Even as a foreigner you have this right. At £3000 the amps list price it is not something they can dismiss.
In closing in April 1990 a unanimous board motion was carried to sack Adrian Walker from the original Deltec Precision Audio. I invited him to join the second version of Deltec when I founded the company in January 2008. A very bad move on my part.