urinary catheters

I am having a hard time getting paid from our DME provider for catheters. I work in a urology office and we use catheters a good bit to get clean catch urine cultures. I keep getting denials stating that "service was not furnished directly to the patient and/or documented." I'm not sure what they are talking about since the catheter was given to the patient in the office for the culture. The patient didn't take it with her out of the office but the cath was used in the office. I'm not sure what else to do. Any tips?