MTN ****med me of my money

MTN ****med me of my money after signing their contract for month to month data and paying R1000.00 upfront it’s been 7 days and I have no internet and they keep on making me wait now I wanna cancel and go for a different service provider they saying I cannot get my money back. After them failing to to keep up to their end of the deal of me having internet this is ridiculous and very prejudice