Recent Surgery Bill for self pay (no insurance) was 5 times the good faith estimate. Next steps.

I had a procedure done recently that I had to pay for out of pocket as insurance would not cover it. The hospital provided a good faith estimate for 26k, and I paid half up front. The procedure went well with no additional items or complications. A week later, I go on the hospital's website to set up payment for the remaining balance and am met with a summary bill for 128k bill. I could understand the estimate being off slightly, but by 500%???????

I am requesting confirmation that this value is correct and an itemized bill. Are there any other steps I should take to dispute this? I just don't understand how this happened or what I'm going to do. It took me 3-4 years to sace up for the procedure when I thought it was 26k. I just don't understand how they could be off by 500% when there were no complications or additional procedures/steps ordered.