Mondo and mtn incompetence

I am currently having a terrible experience with mondo and mtn as well. Mondo called me and offered me an upgrade on my contract and I agreed to a sim only deal and the lady loaded a home Lte deal that had made my one and only mtn useless. I can't call, I have no internet on it I can't receive call of their error. And when I try to reverse it I'm being sent from pillar to post between them mondo and mtn Mtn can't cancel cause it was done by mondo Mondo says it will take 7 days to reverse it and in the mean time I am stuck with no phone or data