I would not recommend any qualitative data coding service, especially if you intend to submit your work to a peer reviewed journal. Is there a reason that you are not doing this yourself?
If you have too many interviews, Nvivo is a good software for processing qualitative data (especially interviews), however, if you have only three or four interviews, I would recommend that you do the coding yourself because the software might fail to capture the nuances the researcher is looking for and could discard differences and focus on commonalities, resulting in the loss of precious data. Good luck.
In addition to NVivo, I suggest you consider MaxQDA (a german software), Dedoose (an online application), QDAMiner (it has a free lite version) and AtlasTI. Best regards.