Poor Service an False advertising

Woolworths online had a special for 3 for the price of 2.I choose my items. Once added to the cart, I noticed that the discount did not apply. I called customer service and was told that it could be an issue. I was given a reference number and if there is a problem the difference will be refunded. I completed my order and I noticed that amount was correct. I paid for the order. After paying for the order, I noticed that 1 item was there, I did not get the free item. I called the call centre and was told that there is nothing that can be done as I accepted the terms and conditions. I was told that the one item was not in stock. I should have been given the opinion to choose a replacement item online before I paid. There is no function for this. Pearl was the lady in customer service who I spoke to. She was extremely unhelpful and rude. I asked to speak to a manager and I was told that no one is available and she is the only person who can assist me. She did not want to hear anything I had to say as I accepted the terms and conditions. This advert is misleading and wrongful. This is false advertising.I paid for 2 item expecting one more free. I have since called the call centre twice and asked for a manager to pl call me regarding this matter. No one has called me. I also requested a manger to listen to the calls and come back to me. No one has. If management cant assist a customer, what example does this set to staff? Woolworth prides them self on customer service and a high standard. It sad to see how staff can damage this and there is no accountability for assisting customers. I had to request that the order be cancelled and I was not give this as an opinion when I spoke to Pearl. This would have been the right thing to do. I think Woolworth is gone too big to be concerned with a single customer who always shops and Woolworths.