If you bought it recently, you probably qualify under Dapol's 1-year warranty. Dapol themselves doesn't do the warranty work, but a UK outfit called DCC Supplies does.
I don't have any experience with them because I'm past the one-year time-span.
But I haven't heard any complaints about them.
Even if it is outside of a year since purchase, perhaps you can at least purchase a spare motor from them.
And as for DCC in that thing, it is a hardwire job.
The only Dapol steam I know of that is DCC ready is their tender engines, and the 57xx Pannier tank engines.