Complaint on Vodka Johannesburg

A few months ago my team and i submitted a proposal for sponsorship for a tour that we were about to embark on. We submitted this proposal to one of their executives. We were told that she is the person responsible for sponsorship. She is based at Vodka's offices in Johannesburg. A long time passed then one night close to midnight she sent a message requesting another brief/profile of the tour and our organization which we sent straight away. Many weeks passed and we had forgotten about that proposal, this executive in Johannesburg sent us a message in response to our sponsorship proposal. The message says "the board has approved our sponsorship of worth R200 000. She also said that the guy in charge loves Wiskey and as a gift to the sponsorship approval in that same day, that we should arrange R500 for this guy's Wiskey so we paid that R500 as a gift to the executive. She confirmed that the next Monday, our contract will be sent to us for review and signatures. It has been a few months and no contract has come. In the interim, every time we call her she would say things like, "next week" or "I was in hospital" or "i will deal with the contract the next day" etc. This went on for ever. Recently when we followed up with her she began to speak a different language like: "Send me an email" or "I will call you back" or "I need to speak to the board" or "we will look at your proposal and let you know" etc. The worse came today. We contacted her to inquire and she is now saying that she has never approved any sponsorship. We have her confirmation in writing and we have proof of payment for the gift to the person in charge as she suggested. She specifically asked that Vodka (energy drink) be the only energy drink on our project. She is denying approving the sponsorship. We already spent a lot of money thinking that Vodka South Africa will honor their commitment. They need to address this issue and honor what they had said. They also committed to our projects next year without us asking them. The sad part of this is that this lady executive now threatens me by saying "her legal team will advise them on the subsequent steps". I demand an apology and payments as promised.