LinkedIn Sr. Software Engineer interview questions

A LinkedIn recruiter reached out to me on LinkedIn for a senior software engineer role..although I'm a better fit for junior developer (I mentioned this to them). The two interviewers called and asked me two questions (first was testing how well you remember strings/character manipulation, second was mergesort). The interviewers were completely quiet during the interview, and even when I asked questions, I had to ask several times because they were not listening. They seemed completely uninterested, and I had a feeling they decided not to like me after I failed to remember some concepts for the first question. Overall, horrible experience. I've had bad interviews in the past, but none where I felt the interviewer just didn't care to even listen. I would never interview here again. Even the interviewers did not seem like they enjoyed their job.