Global Question

I had a claim for an office visit deny for DOS 5/1/13 for post-operative service included and is part of the surgical procedure. This person had lithotripsy (procedure 50590 originally done on 12/20/12. He had the same procedure done again on 2/15/13 and we used a 78 modifier. Cigna denied this 5/1/13 claim as global from the 2/15/13 claim. I explained that the post op starts from the initial 12/20/12 claim and runs 90 days from that initial procedure. The customer service person at Cigna said that their softward McKesson denied it and that I would have to prove through some AMA literature that this should pay. Do you have something for me or am I wrong. This has not happened to me before.
Thank you!

re: Global Question