Amazon/Chase Bank Caused my credit score to drop

So I went to purchase an item from Amazon. They said if I use thier credit card I will get the item for free. So being I am good with that I selected to pay that way.

They declined me which is odd but I paid with my bank account and all good... well until I got an email from Chase saying they declined me and right after an email from my bank saying my credit rating dropped a few points.

Now I have a good rating (over 700), I have around 20k in open credit and penty of money. I did not need or want another card but when Amazon said I would get the item for free I of course would choose to go that route.

I contacted Chase and they told me to contact Experian. I contacted Amazon and they told me to Contact Chase. I can see I am in for a run around with no recourse.

My advice is don't fall for these credit offers no matter how good your credit is. I can deal with being declined for no reason or an unknown reason but to do this with no result but hurting my credit score really sucks.