New Balance fell of the ball

I ordered and paid for new shoes on New Balance's website in Mid-November. About a week later I received an email saying that unfortunately they do not have stock in my size anymore (take note there was no such warning on their website) and that they will be refunding me within 10 working days. About 3 days later I received a refund, but only for 80% of the money that I paid. I waited the until the 10 working days passed, but the money never came. I emailed NB and they said that the issue has been sent to their finance department. Another week passed and still no money. I emailed the finance department about the issue, to which they responded with a Proof of Refund, which only shows the 80% that they paid me. I wil never buy anything New Balance again!

Oh and to add to all this, a week after my initial order the shoes (in my size) were for sale on OneDayOnly.co.za and New Balance was the supplier