I Have A Medicos Cold Therapy System Used Mostly For

I have a medicos cold therapy system used mostly for the back. The bag that attaches to the pump has a leak on the outside bag. I need to order a new bag that attaches to the pump lines. How do I do that? I live in El Paso, Texas. The machine belongs to my sister. She purchased a replacement bag for the system and I obviously need to do the same. She use to live in Garland, Texas.