Quicken Loans Hard Credit Pull and Lied too detroit Michigan

I spoke to Keely Czartorski about getting a pre-approval for a home loan. She did a hard pull on credit and then told me that my credit score wasn't high enough to get a loan without a co-signer. Then a couple days later I recieved a letter from her saying that my score was 687, and the reason for denial was insufficient funds to close. Close on what? I haven't found a home or anything on that journey as of yet so how does she know what funds I have available to me. I'm a first time home buyer and from my understanding I only need a 620 so how am I unapproved. These people say they are there to help but in reality they just want you to sign up for Quizzle.com and lower your score by pulling it with denials for no reason.