Price increase during checkout

First I am a veteran so I do appreciate Dell offering veterans a 5% discount - so thank you!

On to my question: Could someone please tell me how the DellDC15255 price went up THREE HUNDRED dollars WHILE I was checking out? How can I get the computer for the price that was advertise during checkout?

I started to check out on Monday Oct 13, 2025 at 4:54 EST, and the price on the screen was 398, I put in my name and address and then was asked for payment information but I noticed that the price went up to 699 dollars by that time it was about 4:55 EST.  Can someone explain that to me?  I have a couple screenshots and have sent them to a Dell rep and he told me "the deal has expired", he said he would talk to the team and get back with me, he did say it might be a while., that was Monday at 5:30.  I emailed him on Tuesday and have not heard back from him.   From the chat :  "You are welcome I will be working with the pricing team

( 30m 18s ) Dell Advisor -xxxxx: and as soon as I hear back from them

( 30m 25s ) Dell Advisor - xxxxxxx: I will email you the best deal for your purchase. 

I called yesterday and couldn't resolve this, what can I do?

If a Dell rep replies and instructs me to go to direct messages, please send screenshots on how to do that, as I have tried to do the instructions left by a rep in July of this forum and the rep didn't include enough information and my screen did not have the same options.