Farmdrop Content interview questions

The interview process was a lot of fun. I met with one of the managers responsible for brand development. He was very friendly, we exchanged great ideas, discussed how I could develop professionally in this role and agreed to stay in touch. One day after the interview I sent a follow-up email with some more suggestions for developing content for Farmdrop. My interviewer responded that those were great ideas and we should stay in touch next week (this was Friday). One week later I sent another follow-up email asking if they need any additional information and when I should expect any updates - no answer. A couple of days later I send another email and try to give a call to a number on the person's email signature - no answer. I send an email to a customer support email explaining the situation and they inform me that they will pass that on to my interviewer and he should be in touch shortly. More than a week later - still no answer. This is when I realise the person is purposefully ignoring me. I can understand if the company wants to go with another candidate or I am underqualified - simply send an email and explain (especially when we agreed to stay in touch). But so actively ignoring after I sent so many emails? I think this is extremely unprofessional and did not realise these things would be happening in 2018. Absolutely terrible experience filled with false hope and disappointment.