Time Capsule Blinking Amber

Hi. We just purchased two IMac 27 inch's and a time capsule. Just recently, the time capsule started to blink amber, and after further inquiry, I discovered that the disk storage space was low because of all the backups the time capsule was making. I then clicked onto the time machine icon, accessed the time capsule memory, and deleted over 800 Gigs of backups. The time capsule we own has 1 TB of memory space. Although the files I deleted do not show up anymore, the Time Capsule still believes that the storage space is low, and the amber light keeps blinking. How can I resolve this issue? I want to be able to (a) make the time capsule read that I did, in fact, delete the files, (b) resume backing up all of my Imacs information, and (c) prevent this issue from ever happening again. I was under the impression that Time Capsule automatically replaced your old backup with a new one, but apparently it does not, at least in my case. If anyone can direct me to a support website, or tell me step by step of how to resolve this issue, it would be greatly appreciated. Thanks!