Leaving vodacom due to crazy rates

My contract expires in 3 months. I wil definitely not renew or upgrade my vodacom contract. I bought n power data bundle just now for R3 and the 50mb date literally depleated within 60 seconds an not minutes. Im serious if i say 60 seconds and not minutes. How is this even possible? I wont buy it ever again because vodacom takes money and doent provide one with the actual data you paid for. Very unsatusfied and will leave this supplier soon