Very bad delivery service and I want to cancel the order

The delivery service using by Dell is not very convenient for me. It really gave me stress. I waited the delivery but I didn't get it. I wanted to change the delivery address, date and time but I couldn't. I tried to cancel the order when I couldn't get on time but I can't choose the option. The option for the cancellation is disabled. I just want my money back now. I don't have the whole day to wait for delivery.