I think the best way (in my opinion) to handle such situation in office (where you will have to go regularly) is to cultivate metta toward all beings and in particular, metta toward the person(s) with whom you are not in good terms. Do Ariya (even anariya) metta bhavana daily. And if possible, do metta bhavana saying person such and such be happy and healthy. In due course of time, the situation and relation with those persons will improve and you will be surprised.
In office it is not possible to avoid people working in same office. Hence, the best is to cultivate metta. My personal experience is that it definitely help, although may take some time.