Nedbank does not deliver on promises

I opened a Nedbank PayU account online and a promotion was advertised awarding 1GB of data and a R500 Edgar's voucher. The terms and conditions state that the 1GB will be awarded upon opening the account, of which I have received, and a R500 Edgar's voucher after 3 transactions are done on the account. I have done 3 deposits into the account and have not received my voucher yet. It has been a week since I have emailed the provided email address *** and have not received a response. Their automated response advised that they will respond in 48 hours. I raised the matter via an online chat on Friday 2nd August 2019 and was advised by Nonthando that she was going to escalate the matter to her team leader and I will receive feedback on Monday 5th August 2019. I have not received any feedback. I emailed the so called complaints address on *** yesterday and still have no response. And according to the automated response they will respond in 24 hours. I am highly annoyed at Nedbanks refusal to respond to my query and the fact that they do not deliver on their promises: both on the promotion and on their automated responses to get back to customers. It is highly unprofessional and should I still not get feedback after this I will be emailing the CEO.