+1 on the importance of communication. It only takes a few seconds and would put the OP's mind at ease, negating the "need" to call every day (multiple times). I get it, I really do. When I lay down $, I want to know where my money went to. I get obsessive about it as well. Perhaps not to the point of calling/emailing multiple times per day, but I definitely get anxious, especially if I'm told one thing and experience another.
I suppose the moral of all this would be the following:
1) Set the customer's expectations early. If the shipment is going to take three months..tell the customer it'll be four. That way you'll end up the Hero when it comes in early, yet not the tyrant when the delivery falls behind!
2) Communicate with your customers on a routine schedule, just to let them know how things are coming along. You may not have any news, but sometimes no news is better than not hearing anything at all.
I'm just sayin'!
PS. I've learned the value of item number 1 over the years with my wife and my anticipated departure from work! I used to tell her what I thought she wanted to hear "I'll only be another five minutes" and then had to hear the dissapointement when I did not come through. Now I just tell her "I'm not sure...maybe an hour?". And all is good when I show up in half the time! What can I say, I'm just keeping it real..and keeping the "customer" satisfied!