Defective goods and bad attitude from owner

Bought cartridge for HP printer on Thursday afternoon. Tried printing with it on Friday and it left a big white streak down the middle of the page. I returned I on Saturday morning and the staff in the shop accused me of using the entire cartridge. They requested that I bring my printer in to test the settings and see if I did in fact use it. I duly brought took my printer in only for them to tell them that they could not see it on the printout. They refused to acknowledge that they could have been at fault and started shouting at me in the shop. Needless to say, I picked up my printer and waked out. Whilst I was in the shop there was another customer complaining about the same thing. They are charging for goods and not supplying them. I consider this *****.