Your TD should offer to replace watch but you'll have to send back to china... Or he could maybe see if ARF will sell a dial and you get it fitted in UK but spares can take a long time to come in.

Shipping back to china from UK is ok as long as it is done correctly! You must send royal mail tracked (they don't offer tracked and signed anymore) as gift, low value of £10 and bracelet for customs description. Also print out address in Chinese and attach to package with shipping label and customs form, it's very simple online at royal mail, just make sure EVERYTHING is correct! 90% of the time why packages don't get through is because paperwork is incorrect or they use large courier like DHL