rejected due to quality!!!

This is stock, not journalism. You can fudge and there. Put some blue sky in that bottom image. 😉 Avoid centering your subjects, like you did with the image below the centered flower. The crop may be a little too tight on that one.

What is a professional camera? It is not the camera but the person behind it. Although having good lenses does help.

Your first photo does not follow the rules of composition, the photo is not focused properly, there is noise in the background and it is a little dark.
[edited by moderator]

Your professional camera creates noisy pictures…

It's not the camera's fault. It's because the photographer does not understand the quality concept! 

The flower picture is, as an additional issue, not in focus.

(Edit: before the correction of your post by a moderator, only the two first images were visible.)

Third:

Noise:

Fourth: focus:

Fifth: DOF. Not enough of the apples are in focus. You should enhance the contrast, open the shadows, and a small punch on the vibrancy would enhance the asset.

Your last: exposure! Look at the histogram. Blacks are missing. Whites are missing. Enhance the contrast, add some blacks, whites, add some local contrasts (called texture and clarity in the Adobe world), lift the shadows.

And then, you need to correct the chromatic aberration.

You could also crop at the right, this small line out.

As a general: your aperture is too low here, you could really have worked with something higher: 4-8, I would guess. The image would be less soft, more crisp. Learn to set up your camera manually instead of using one of the automatic programs.

A 700D with EF-S lenses is not a professional camera, the camera is, however, able to provide professional grade images, as long as you stay at a lower ISO value to lower the noise level. ISO 3200 is definitely a too high ISO level here for stock, even that I would use it for event photography without hesitation, even on an APS-C sensor type.