Citizenship

My husband has his Citizenship Interview yesterday and we got really disappointed. He passed his reading, writing, and Civic test in first 5 minutes. After that he had a conversation on many different topics like family, kids, work, business. The officer was really not nice and asked questions within 45 minutes jumping from one topic to another. After that, he asked if my husband ever voted in US. He replied NO. The officer had a really heavy accent and sometimes it was not easy to understand him. He asked some other question about voting which my husband was not sure what the officer asking and asked the officer to repeat the question in a different way. The officer said he doesn't have to to repeat the question and said that my husband need to have a second interview as he doesn't speak and understand English. My husband was really shoked. He passed all tests, he talked to the officer for 44 minutes... He owes the business and 30% of his day on the phone with customers and vendors and.... according to the officer he doesn't speak and understand English.
We really don't know what to do now. Should we send a complaint? It was really obvious too that the officer had a really bad attitude and was speaking to my husband not in a nice manner during the Interview.