Mea culpa.
If you didn’t fill out an app, then there’s obviously no app they’re trying to complete, and have no need of one of your utility bills, or any other document from you.
Is there a prepaid envelope for returning the requested utility bill? If so, write FY! on it and mail it back on their dime.
I got those years ago, and after doing the mailback on each, they stopped.
Also works well on GOP solicitations, AARP crap etc.