MTN BLACK FRIDAY PROBLEMS!

I signed a contract for 36 months getting 40gb anytime data and 400mins during Black Friday. I only received 20gb and every consultant I've spoken to has said they not sure why I've received 20GB but thats what the system shows I qualify for every month, they then refer me to retentions. When they put me through to retentions I wait over 20mins with no answer. I've tried 5 times already with no answers. It's becoming frustrating not been helped.