Dollar Tree IT Operations interview questions

I applied for an IT Operation position. I was contacted by Dollar Tree via email about 1 month ago and was asked to provide responses to a list of questions, which took over 1 hour to complete. I have sent several emails asking only for an acknowledgement of my responses, only to hear nothing. How hard is it to reply with a " We appreciate your response and will be in touch should anything further be required"? Very inconsiderate and disappointing given the effort that was put into proving a thorough response.