When you buy any third party lens of ANY make of camera, you do so at your own risk. This is not specific to Canon, it applies to Nikon, Olympus etc. For support with this lens, you need to contact Sirui directly as it is their equipment.
cheers, TREVOR
The mark of good photographer is less what they hold in their hand, it's more what they hold in their head;
"All the variety, all the charm, all the beauty of life is made up of light and shadow", Leo Tolstoy;
"Skill in photography is acquired by practice and not by purchase" Percy W. Harris
