if I am working hard pro se, and there was a witness at my last trial, can the attorney who summoned the witness withhold their credentials from me?

I (defendant) recently had an evidentiary trial for small claims, where the judge made final judgement in favor of the plaintiff for full amount plus costs. He didn't lay out the full amount for time at that time. The witness that appeared isn't the person that signed the affidavit to be a witness that is found in the case files. When I've asked for the witness credentials on my case and debt, the plaintiff has refused me of that and the court never needed anything on file from the witness. Is this to code? Are they going against the law by withholding that information from me?