Data roll over-prepaid

I called on the 25th May and spoke to veronica regarding me speaking to a guy at MTN call centre on the 24th April because after I bought data I got a sms saying that the free 1GB last for 30 days so I called to confirm that the free 1GB of data will last for 30days and the 1GB of data I bought will last for 60days. The guy on the call on the 24th April confirmed I am right. Then on the 24th May my data expired. I called on the 25th May and spoke to veronica and she confirmed that she will get a supervisor to investigate and call me but it's the 13th June with no call as promised.I called today and got told it was escalated but there is a strike going on so I will get a call back because MTN going on strike or whatever is not my issue. I want a call from the call centre manager and I want this issue to be resolved and my data to be given back to me because of MTN's error and being misinformed.the agent confirmed what I said.