Pinterest Content Manager interview questions

I received an e-mail asking for availability, and once we had that, went through a brief 30 minute phone interview. I was told they liked me on the Friday following my phone screening, and would like me to come in for an on site interview. I was supposed to hear from them the following Monday for next steps. I never received a phone call at the time discussed. I followed up via e-mail and received nothing. I cannot believe a company of this size and with a good reputation would be so unprofessional. It turned out to be a complete waste of time.