Delivery of server racks

I hate it when I have to tell people that something won^t be ready for the date that we have previously established. Do you know what I mean? This is really frustrating and I don^t know what to think about it. When you tell someone that his product or service will be ready for this particular day, you feel terrible when you have to say that you were wrong right from the start. The person might feel that you have cheated him or her. Am I right? That is why I try to avoid situations of that kind and I am sure that this is the right choice in this situation. Recently I have been waiting for a delivery of server racks to my store as there were many clients asking about them. I have promised them that they will be here on that day and I knew that they need them. The problem is that there was a delay in this delivery and because of this we had to inform our customers that the server racks won^t be available as soon as we thought. This is a serious problem. I am afraid that the customers might feel offended and that they won^t do business with us again. That would be a tragic situation and I hope that those server racks will be here tomorrow. Otherwise we will have serious problems and I don^t want to think about it all.