Refund not processed

I ordered a set of pots from Grabitall, paid for it, mid June 2021, advised that delivery is between 7-9 days. I was later advised that my order could not be completed as the pots were no longer in stock and they do not know whether they will receive new stock, i was offered a credit on my account but i opted for a refund, i was asked for bank details which i provided immediately. I have been following up but now no responses anymore. I used to liase with Nicolus who kept promising to check with the finance team and come back to me but never did. Please help this is grossly unfair.