Currys lose delivery items with courier, and won't refund you until they find them!

I ordered it item from them on Saturday for 'guaranteed next day delivery' (Sunday).
On Sunday morning, I got an email saying my delivery had been 'upgraded' to Tuesday! I rang to complain, and was told the DPD had sent it to the wrong depot, and it would DEFINITELY be with me on Tuesday.
On Tuesday I got an email saying my delivery had been 'upgraded' (again) to Wednesday. My next day delivery has now changed to a four day delivery... I rang and cancelled the order, and they said they'd give me my money back straight away.
They didn't...
I've just got an email saying that now my parcel has been found and returned to Currys, they will begin to process my refund.
I never had the bloody thing, and I didn't loose it!
Currys put the business risk on me, and made sure I would pay if they never found the parcel that DPD had lost.
Avoid them like the plague!