Tessian Graduate Commercial Program interview questions

I want to be as impartial as possible, but Tessian have sadly let down during the interview process. I was hopefully positive during it, and the first interview call went well - though didn't seem particularly difficult or different. Pretty standard questions. They then ask you to complete the email strategy. I've designed one before very successfully, so thought this was a great task. I completed and submitted. A week later I receive a very generic email advising I had been rejected. No advice as to why. I've been in contact for feedback but received nothing to my emails. Tessian seem like a good company, and one worth working for. But very few other companies become as impersonal as soon as they decide it's a no, so my belief in that has strayed. Would I recommend applying to others? I'm not sure I would anymore.