Lie about the stock and now I sit with a problem

I have been to the Hi-fI Corporation store in sturbensvalley, New Store. I got a quote for the insurance on a Pioneer Amplifier. I asked the sales lady if they have stock in the shop and she said yes they have lots of stock. So I got the quote and send it off to the insurance. The insurance pay out the amount of R4999 for the amplifier. This morning i phoned them to tell them i will be fetching the Amplifier. They then told me they dont have any stock since last week. So she **** to me because where is the lots of stock. I can now not buy amplifier for R4999 because they dont have anything on the floor for this amount. The insurance is not going to give me more money. I asked the manager if he can then give me discount on the one I got a quote on a discount seeing that it is on display. His words was 5% that R250. Does he really think I am that stupid. What am i suppose to do now. I think the retail must give me something now for the amount of R4999 like the quote I got for the insurance pay out