No payment received one month after verification

Won just over £30 and requested withdrawal on 1 July. Received an email the next day asking for verification docs. Emailed these back the same day and was advised the next day that withdrawal had been authorised and I would receive the money within 3 to 5 days. Waited a week and no money received. Therefore contacted them again only to be told that refund was not possible on my Mastercard. Reluctantly agreed to a cheque refund even though they insisted on a £5 administration fee. Was advised it would take up to 10 working days to be with me. 2 weeks later no cheque received. Contacted again to complain. Was promised the cheque would be reissued. I have still not received payment and don't believe a cheque has ever been sent. This casino seem to just make excuses hoping you will forget about getting your winnings!