Samsung S21 FE promotion with free Samsung tab A7 lite

on the 18th of February 2022 I upgraded through Mondo MTN to the S21FE with promotion of the A7 Lite Tab and the upgrade was confirmed on the 18th February. I was told I would receive a voucher to claim the Tab in store. A week later I got notified of delay in delivery of my phone. I then only received my phone on Friday 25 March 2022 and as I suspected no voucher. Following numerous call with MTN, Mondo and Samsung I have had no luck sorting out the issue every person passes me on to the next and eventually i get put through to some department that doesnt pick up. What is the use of having a customer care number if nobody ever takes the call? I get told they might not be able to help me because the promotion expired however this is not my problem as the upgrade was confirmed on the 18th of February and the deal was the only damn reason I went for this phone. Absolutely shocking customer service. Assistance please somebody