One thing I don't understand is, did you report this user to the SS and they do nothing?

This is not only the agency related issue. You can sue a company for using your image without permission if they do not buy from you. And you can prove these photos belong to you with the original files.

Quote from: Ipek Morel on March 09, 2018, 01:48

SS accept mobile photos but you have a very low chance to sell these photos as rights managed. Nobody pay 100$ for these photos. Mostly bloggers will buy these so you get very little income.

So keep shooting with pro equipment 

When a customer see the thumbnails and the blurred previews on the Shutterstock site, tell me how he can understand if the photo has been shot with a $100 smartphone or with a $50.000 Sinar P3 camera with a 100 Megapixels medium format back?

Customers can see the image resolution also they have right to decline the photo for low quality.

Also, it's not the only camera that makes the difference. You need to use good lighting too. That's make the real difference even in low resolution.

iStock focused on exclusive contributors, they want images that the buyers can only find on iStock. If you upload only to iStock they pay very high commissions in comparison to non-exclusives. They do not want to pay for images that buyers can find elsewhere. Actually, they say be exclusive or leave. As you noticed the "Microstock Poll Results" on the right you can see exclusive contributors earn nearly 5 times more than non-exclusives and 3 times more than Shutterstock contributors.

I have acquaintances who earn well in iStock and all of them is exclusive. So you need to be exclusive or just leave.