Can I object to a dismissal without prejudice during a pre-trial hearing?

I have already had two mediation session with a credit card company trying to sue me over an very old debt. During the mediation hearings the Plaintiff has been unable to provide any documentation validating the debt, or any evidence for that matter. After the last mediation hearing, I requested a trial and my pre-hearing is in 3 days. All of a sudden I receive a dismissal without prejudice that the Plaintiff wants to sign so they can file it before the hearing. I'm not having! They filed a claim with no evidence at all, they expected me to fold and pay. I want to attend the pre-hearing and object to the Dismissal without prejudice. Is this possible? Can I even object since it's just a pre-trial?