Just want to have a slight rant...
I recently bought a pair of ankle boots on M&S online using a 20% discount code. Bought size 7, but they turned out to be too big when I tried them on at home. Took them back to my local store on Saturday hoping to try a size 6 and get an exchange, but they don't stock this style in store apparently.
So, I gave them a ring, explained about the incorrect size and asked if I could do an exchange (and therefore still get the discount). But they don't do exchanges. The only thing I can do is to return the boots and get a refund and then re-order the correct size. At the full price.
Grrrr...