Didn't give a full refund for returned goods!

My mum ordered three pairs of shoes in a size 3 which were all received in one delivery and in good time. No complaints there. However, not one pair of shoes fitted, they were all far too large and needed to be returned (they fitted my feet and I am a size 4). I made the wrong assumption that to return these items would be free as I do much of my shopping on the internet and most companies offer free returns. I had to pay £6.00 to return all three pairs of shoes which I accept is my fault for not reading their returns policy. HOWEVER, when I received emailed confirmation of the refund, only two pairs had been refunded! They were all in the same bag, sent by Royal Mail Recorded Delivery. Not being able to email the company as it wouldn't allow me to do this, I had to telephone their 0844 number. My initial thoughts were that they hadn't refunded me for all three pairs as they wanted me to call their expensive customer service number. When I telephoned, after about a couple of minutes waiting to get through to somebody the lady didn't quibble about the refund and said it was an error in the warehouse (how did she know this?). This confirmed to me that it was purposely done either to make money from their 0844 number (they share the revenue with the service provider) or in hope that I would forget about the non refunded item. This is such POOR service not to mention a bit devious. Both my mum and I will not be making further purchases from this company and we will warn others not to do so. Looking at the reviews, it appears many others have had problems so beware.