Consumer Bankers Association interview questions

Applied online and then got an email requesting a 90 minute interview. Definitely made me nervous as I thought it would be more technical or possibly with several other people. The interview ended up lasting about 40 minutes, and was just with one individual. I was obviously relieved it was only 40 minutes, but I just found it a little inconsiderate because with the questions I was asked there was no way it would've taken 90 minutes. I guess better safe than sorry but still. Pretty standard interview questions for an internship position. Interviewer was pretty nice. However, he told me I would either hear back by the end of the week or the next (the interview was on a Tuesday). It's been almost a month and I haven't heard anything. I actually went into the interview already having another internship offer, but I find it very rude to not receive a rejection email and to just be straight up ghosted. In the interview the interviewer himself even said he doesn't like to leave people hanging, especially with finals and Christmas coming up. So just odd behavior and unprofessional.