Credit Card Lounge

I have a need to see proof of my signiture on a credit card application from 1994. I suspect I didn’t sign for it (co-sign actually) but I’m not 100% positive. I called to have them send me proof – they refused saying they’d need a court order to do so…. Huh??? As of right now – I’m listed as joint owner – so I closed the account so no further charges could be made. I just find it hard to believe I have to go to the courts to get proof… True / or not true? It’s USBANK if it matters.
Update: Just saw Mary’s response. There were charges made to it (18k!!) by the other joint owner – it was a written application – and that joint owner had a history of signing my name on things – I believe this is one of those times. Again – the credit card company said they’d provide it – just with a court order to do so and not just because I request it. While I have called my attorney – I was hoping there is a better way to simply get a copy of the original application. That is what is difficult for me to believe!! I’m thinking of just calling their fraud department next – but my attorney is back in Monday – maybe best to wait for him…