Are you reporting the correct diagnosis? 82270 is the screening code, for fecal occult (guaiac) which should have a V-code diagnosis, such as V76.41, not a symptom diagnosis. One of these fecal occult screenings is allowed each year if the patient is over 50, whether you result only one or all three of the cards...so make sure you're not billing one at the time of service and the other two when they get sent back, or they'll deny as a dupe.
The 82272 is used when the patient has a symptom, such as rectal bleeding, and the coverage is pending deductible and co-insurance.
The G0328 does not specify guaiac, but there are other FOBT tests out there that use immunoassay rather than the peroxidase, so it might be appropriate depending on your methodology. Check your local policy to see if they prefer this code over 82274.
Let me know what you find out.