Bad and false selling

I upgraded my contract at the Eastgate Vodacom Shop, Sales person Thabiso sold me a Alcatel Tablet and oversold all the things that the tablet is unable to do after he persuaded me that this was the best tablet. Today i took the Tablet back to the store and fortunate for me he was there, he denied everything he said about this particular tablet which you cannot even make a telephone call on it if you don't buy an App online. He said he assumed that because of the package I'm taking, if i load airtime the tablet will work, which is not the case with this gadget. Amongst the questions i asked him was if this can make phone calls and if my son will be able to use it for his tertiary purposes - and his words were "This is the best". Only today did i discover that the tablet i wanted they did not have in stock. So he took an easy way out by selling me something that does not fulfill my purpose after i had explained to him what i needed it for. Instead his supposedly store manager said they will take it to their tech department and they will give it back to me. So is this the integrity of Vodacom and how they treat their customers.?