Bank details

I placed an order and a few days after I made payment, I received an email stating that one of my items was out of stock and was given the option of leaving the money as a credit or requesting a refund. I asked for a refund. They then asked for my bank details which I sent. After sending my details, I realized I made a mistake with my acc no. Within a minute I advised them of my error. The person in that depth never bothered reading my email where I advise of my error. They then refunded the money to the incorrect account. I liaise with them and I was told to contact MY BANK?? I then told them I will put this on Social media and then got a response saying they will refund me when the money pops back. It's been over a week and have not heard from them.