Lack of service

I recently won money from Easybet and withdrew the winnings. I received an sms from OTT Nedbank advising of a voucher code and pin. When typing it in at my nearest Nedbank it says it's been used. This is nonsense as I've never used it. I contacted NEDBANK OTT who keeps cutting my call. Why do I even opt for a NEDBANK option knowing I'd go through all this for my own money. Useless and delayed. Why should I wait for my own money?