Based on your interaction, it seems these resolutions are important part of your job. Not sure how I can help here, but, the most basic thing you can do is listen to the person. While you do that, get as much info as you can, and provide them with solution if you can. Else, ask them that you'll get back, and get an professional opinion from people you trust and know can help you in this regard. At the end, based on all inputs, take a call and be fair and honest in providing the response, while keeping in mind that the way you convey anything is more important than what is conveyed, so, frame it across