No Refund

On the 15th or 17th January, I paid for what I thought was a Samsung Galaxy S7 tablet + Keyboard. It turned out that it was just a S7+ keyboard , not a tablet + keyboard as I thought. I immediately informed them of my error the very same day by email and followup calls. I was asked for my bank details which I provided them with, but to this day I stilk haven't been refunded. On my last call I was promised to be called back once they'd established the reasons for the delay, but no one called.