Unprofessional call centre

I am a long-time Nedbank client. Today I received a call from someone on behalf of Nedbank. They thanked me profusely for being a Nedbank client, and offered me a special product as a thank you. When I told them that I am not in need of such a product, they hung up immediately without saying anything further. I find this very unprofessional, especially considering how they had just stated that Nedbank values me as a client. Nedbank needs to review the quality of the work that these companies do on their behalf.