Worst customer service ever

My father went to upgrade his phone on Saturday the 13th of November. He wanted the new Samsung fold. Kuki at Vodacom Lydenburg told him everything is fine they just have to wait for the stock. He was even told the contract will be R200 cheaper and that he will still have to pay the R400 of the old device for 2 months, which he was fine with. Today they called him to collect the phone and then he was told he has to pay R10 000 upfront because he doesn't qualify for the phone. I tried to contact Kuki om the cell phone number she gave me, just to be blocked. How can u tell some one that their contract upgrade is fine and then all of a sudden u have to pay R10 000 up front??