Smart Device Issue

I ordered 2 smart devices at the same time. I waited about 3 weeks then was told they were only delivering one. I called last Friday to ask why they were only delivering one on Monday because I orderd two. I told them to not debit twice for the courier because it is not my fault. They did not get back to me about the second device. They always say they will get back at me. I do not understand why I must keep calling and what the problem is. I dont want to end up paying for two when I only have one. This seems like a small thing but it is not because in the end I'll be paying for services I did not sign up for.