I know this has been said before but I 've been having some dealings with h&m customer services (or so they call themselves) re. some online refunds after returning items over two weeks ago.
Anyhow, that process is ongoing but rather than any sort of apology I got a telling off for using a £5 off discount code which is apparently only intended for valued customers (of which I clearly am not) and not for hoi polloi like me! Apparently if I use it again I will have my order cancelled. It's okay, I assured them I wouldn't be shopping with them again and also suggested that they withdraw the (freely available on countless discount code sites) code.
However if you fancy chancing your luck with the rubbishness that is h&m customer services , please do google and use as many discount codes as you possibly can! 
Rant over.