we were gifted one of these last christmas, looks so pretty when it's burning. I haven't finished mine yet so have no personal experience of how easy it is to reuse with a new candle.
if you google 'reuse marks and spencer light up candle' there are various youtube vids , tiktoks and posts on other forums about the things people have tried.
I notice that habitat (via argos and sainsburys) are selling a very pretty light up candle with refills this year, but again I have no first hand experience of this