Expect a call back soon to replace the flamed-out unit.
If you're really lucky it won't catch anything else on fire too.
And when you replace it, ignore the designer
(are they qualified EC/engineer or just interior designer) and connect the primary without the 10% boost.
Was the unused wire capped off?
It is possible on an encapsulated transformer to have windings burn out (and melt the compound) without excessive heat rise on the case.
Let us know what happens!