Complaint Review: Florida Power and Light

I am remodeling and as part of the process am putting my overhead power lines underground. Florida Power and Light (FPL) has a set program for this called "underground conversions". 

Their website has a very specific cost associated with the project, from web page

www.fpl.com/reliability/underground-conversions/faq.html

"Costs Vary. If it is a standard residential service (100 to 320 amps) and the pole is located on your property, FPL charges $651.49. This charge is all inclusive in respect to services rendered by FPL."

The web site continues to state that there are other expenses that are borne by the property owner, which I understand. 

After I picked up my equipment at the FPL stores facility, I received an invoice for $930.13. It was not itemized at all. I requested an itemized invoice and that request was specifically denied by my service representative. I also asked him why the price for my equipment and service was so much higher than quoted on their website and he said he did not know but would advise the web department of the inconsistency. 

I am not satisfied with his response but I did submit the full payment since I need this project to keep moving. I want FPL to justify to me why the cost was not what it had posted on their website.