If the erector tube is broken free, it's toast. If a glass etched reticle breaks free within the erector, it's toast. Unfortunately, Western Field is most likely out-dated enough such that the original manufacturer (I believe Tasco?) won't honor warranty/guarantee replacement or repair.
Luckily, however, it's a cheap scope. Replacing it with like-kind would be cheap.
Buy yourself a higher quality scope and a decent set of rings. You will be glad you did. The scopes they sell in a package deal with new rifles are always throw aways. I suggest a Weaver, Nikon, Leupold, Vortex, Burris and Redfield scopes. Depending on your budget, you can find one of those at a reasonable price that will be far superior to what came with your rifle.