Gas pump splash guard broke and fell in tank

[BB72CHEVKT]

The week before last I was pumping my gas and when I went to remove the nozzle from my tank the rubber part on the end of the splash guard
broke and fell in my tank. I informed the manager and she filled out an incident report and gave me a copy. She told me to get it removed and get her the receipt. I decided I would call the phone number on the incident report to make sure there would be no problems. I called and spoke to an attorney for the company and told him the story including the fact the manager told me she noticed that morning the spash guard was damaged. I told him I had an estime and faxed it to him it was for $272 to remove the tank and retrieve the piece and reinstall the tank. They called the following week stating the were requesting a check and it would be mailed out last Friday. I had no choice but to drive my truck as I did not have time or money to pay someone to remove the tank the weekend after it happend. I removed the tank this last Sunday and got what was left of the splash guard out of my tank. The only part that was left that did not disintigrate was a hard rubber/plastic peice. The other part was gone and in my tank, lines and carb.
I reinstalled the tank and filled it up. I received the check Monday along with a release they wanted my to sign saying this was full and final payment. Well
I went to start the truck yesterday morning and guess what it would hardly run at first it sounded like it was starving for gas. I called them this morning
letting them know I was having additional problems and left a message asking for them to let me know how to proceed. I think if they want a release for all future liability the need to also pay for new fuel lines, filter, fuel pump and carb. What do you think?