No feedback from Nedbank

I purchased Vodacom airtime on the 7/10/2019 on the Nedbank money app, which was never credited even though it went through successfully on my bank account. I have been trying ever since to get the airtime purchased refunded to my Nedbank account. No one has phoned me or contacted me about this matter, i have to make contact with them, upon which i only get told "It's being investigated." This is unacceptable.