Convatec interview questions

I sent in my resume, received a phone interview from HR very professional. I got an email for another phone interview from the hiring manager. After about a week I got an email to schedule a face to face with two managers who were coming down from corporate. I had face a face interview with Hr and the hiring manager. I was told I would be contacted within 2 weeks, I followed up with a thank you email, 2 weeks no word, I sent an update just reminding them that I was still interested, 3 weeks no answer, the 4th week I followed up and finally I received what appeared to be their standard no thank you from HR letter. I understand if companies decide on someone else, but as I understand they never hired anyone in Greensboro. I felt it was very unprofessional, especially since I had gotten to the face to face interview, not to have a follow up phone call within the timeframe discussed.