Poor service and dishonestly

Good day

I bought a phone (Hisense E32 Lite) a month ago from Ackermans Nelspruit Plaza. I had lost my previous phone after doing a simswap of my Vodacom contract number. The lady activated an MTN card for me without explaining that I will not be able to access mobile data in my initial Vodacom simcard going forward in this phone. I'm in a situation now, I'm getting 10 gigs of data in my Vodacom simcard and can utilise it. Why did she not explain this to me because I would have instantly changed my decision. I am compromised and need an urgent resolution please. This is affecting my livelihood. Thanks. ***