Appalling after sales service

Ordered several items at a good price, all showing as in stock. Order arrived 9 days later. One of the items was incorrect. It was labelled with JE James' own sticky label as the item I wanted, but it was clearly the wrong item. I checked their website and the item was now showing as out of stock so I emailed JE James to request a refund. They emailed straight back to apologise and attached a prepaid postage label for me to return the item. I posted the item back to them the following day (with proof of posting). Although disappointed with their mistake, I was very happy with the apology and prompt return service. Meanwhile I ordered the item I wanted from another supplier at a similar price - and it arrived within 24 hours.
10 days later I emailed JE James to ask them to confirm receipt of the returned item and to process my refund. No reply.
Another 3 days later I emailed again to ask for a response. No reply from the returns address, but I got a line from the sales department to say my 'account is not noted regarding your return' and they would forward to the returns department for their attention. No further response.
Another week later I emailed again, attaching a copy of my proof of posting, asking for an immediate response and the refund of my money. Again only a reply from the sales department saying they did not have the 'returns information to refund' and an apology for the 'lack of response from returns'. I replied to say that if I did not get a satisfactory response by the end of that week, I would take action via my credit card provider. No further response.
The following week I finally received a (standard?) email from the returns department saying my return had been received and processed and I should allow 3/5 working days for the credit to appear. My card has now been credited - over a month since the original order.
In my opinion, this kind of after sales 'service' is not a good way to conduct business, and I will not be ordering from them again.