I appreciate I'm swimming against the tide here, but I wouldn't totally rule out sending the watch back. How do you feel about the costs? £9 to post it back or £150 ish for Ado to fix it (at a total guess).
There are obvious risks inherent in sending it back; the watch getting lost for example, plus if you send it back, you can forget about the watch for 3 months. Can you also trust your TD? That said, I've sent 3 watches back in my time and all three were properly repaired and are still working to this day.
I always try and work out how much a fix will cost (watchmakers best guess) compared to the risk involved. If the cost is low, I'll always fix it myself locally, if not, send that bugger back!