Cop Claims Refusal of DUI Case Can I prove with the First Report That i gave a Urine?

I have it printed out in black and white that i took a urine for DUI which was sent off for testing. officer says refusal a month later. What possibly happened please tell me Cops ? How can you change sending off a speciman to not taking one at all. How will this look in court ? Can they dismiss this due to his loss of evidence or make him look ridiculous in trial.