Mondo cell phone upgrades

Received a call to upgrade, which I didn't want to do over the phone, because I wasn't sure which phone to get. Lady was adamant and said my current package comes to an end at the end of May and I should take this deal with more minutes and data. I said then if I do take this deal, can I still go to a MTN shop and upgrade to a phone without a penalty and she agreed that is the case. I immediately complained and logged a call when made aware of this at the shop. According to Mondo they agree with their sales person, but now I have to prove that they are in the wrong. They also don't want to listen to the recording of the said call/upgrade with me. I now have to go back to MTN to help me sort this out. Stay away from Mondo or Rewards Call when they about an upgrade.