Legitimate upgrade or not?

I received a call from a gentleman saying he is from Cell C, from telephone no. ********** , on the 29th January 2019 offering me an upgrade on my Cell C cell phone contract. I told him I didn't want a phone & we agreed on a Mercer Xpression Cloudbook, which I was told he had in stock. He said that delivery can take up to 10 days & I would be contacted by the courier company an hour prior to delivery. I not received any communication from Cell C in connection with the upgrade, which I think is a bit strange, so I Googled the telephone number & a whole lot of hellopeter.com complaints came up. Is this upgrade legitimate or not & if not, how does this "company" have all my personal information. I have been a customer of Cell C for a very long time & I have only had good serves from them, please don't dissapoint me now.