Need help with denial

I received a denial from United Healthcare and I need some help please. The following was billed:

1-12-16 Patient had a D&C (59820) due to missed abortion (O02.1)

This was paid with no problems. Patient sees the Dr on 3-7-16 and he decides to do a Sonohysterogram in the office. (A Sonohysterogram is a specialized ultrasound of the uterine cavity to identify any abnormalities such as fibroids, polyps & congenital malformations.) The following was billed:

3-7-16 99212 w/modifiers 24 and 25 (N96) Recurrent pregnancy loss
58340 (N96)
76831 (N96)
(58340 & 76831 are the codes billed for the Sonohysterogram/SIS)

UHC paid the 99212 and 76831, but denied the 58340. I called them to find out why since those 2 codes are what's billed for the SIS. I was told that 58340 was bundled with 59820 (D&C) and it's still within global period. I put all of these codes in my claims scrubber and it did not show that those codes are bundled. I am really confused on this one and if there is someone that can help me, I would greatly appreciate it.

Thank you

re: Need help with denial

I think you need a modifier on the 58340 showing it's not related to the 59820.