Hi DJBphotoshopUser,Silkrooster is correct, you can't enlarge an image without pixelation, and when released, Photoshop CC will allow you to upscale images with much better results than before.For now, I would recommend trying to rescale the image again using this video tutorial as a guide:
Generally once you uprez an image and saved it with no way to access the original (image in a state before you edited it) there isn't much that can be done. You could blur it, but that would defeat the purpose.
If you still have the image in its original condition, there is software that can uprez an image with fair amount of success. In fact Photoshop CC is suppose to have a better algorithm for uprezing an image, but in all cases, you can only go just so far as the computer has no way of knowing what data was left out, so it can not fill it in for you.
This is the reason why it is so important to start with the highest quality image in the first place and when editing to keep that high quality image just in case you need to go back and start over. But that is hind site for yeah.