Tax nightmare

I submitted my tax returns last month and was asked to upload supporting documents for the return submitted which I did. I then received an email stating that my documents have been received and that my case will be attended to my an officer within 21 days. I decided to call them today to make a follow-up on my case and they keep hanging up on my calls. I have requested for a call back which has never happened and have been on the line 4 times with them only for my calls to be dropped. Can someone please tell me. What is going on with my case as I have been waiting for feedback and it seems like nobody is going to bother get back to me. My case number is ***