Faulty products

I recently went into a Vodacom 4U store in Pietermaritzburg Midlands Mall in order to purchase a screen protector and body glove cover for my S9 plus. The salesman kept on showing me the most expensive options despite me telling him I was not willing to spend so much money. Eventually I consented as he convinced me the products were top of the range and I would not have any issues with them and I spent approximately R600 for the screen protector and another R600 for the body glove. The salesman then put the body glove and screen protector onto the phone for me and handed me the phone. Less than a month later while wiping the screen with my SHIRT the screen protector just fell off. I have been back to the store to complain but was told that I need the original packaging in order to lodge a complaint. I explained that I was not given the packaging by the salesman or even the option of taking it and I was just told sorry they can't help me. I have asked to speak to the manager on two occasions and on both occasions I have been told he is not there. The staff are either lying or the manager is negligent as how can he never be there. I want my money back or a new cover.