KPMG Data Analytics - Associate interview questions

I applied online through my university. I got an interview at my university. Then I got a call a week or so later saying I had an offer, which was exciting. Then I got another the next day and they apologized but said "We made a mistake on our part and gave you an offer that you haven't gotten. You need to come in for an office interview before we can give you a final decision." I found it incredibly unprofessional. I did go in for an office visit because at the time I didn't have other offers. The Dallas office is nice and people are friendly. But I'm still chafing that they told they had an offer for me when they didn't. A week later, I got a real offer from them.