Lane Bryant review: Online panty deal

I received an email a few weeks ago about a panty sale that was Buy 3 get 5 free. I ordered online 6 pairs of panties expecting to receive 10 pairs free. What I received was 6 pairs of panties only. I chatted with an agent about this and was told I had needed to place 8 pairs of panties in my cart for the deal to kick in. That bit of ordering info was not printed on their website. I'd searched around prior to placing my order as I was unsure if my order would get done correctly. I was not happy with the agent's response and sent an email complaint describing the situation and explaining that the ordering instructions were not on the website at the time I placed my order. I stated I ordered the required number of panties to receive the free ones and I should not be penalized for not ordering the panties correctly. I requested that they send me the 10 pairs of panties I was entitled to. Their response was extremely wordy. I was told that that buy 3 get 5 free was no longer available but as a gesture of goodwill I could reorder the the panties in sets of 8 and send the agent my new order number and they would process the sale price. Look, I already paid for the 6 pair of panties and did not receive the 10 free pairs. Why do I have to buy 6 more? I don't expect any resolution to this. I am a loyal customer. This is not the way to handle customer service.