Bad attitide towards the customers and refuse to pay back the money

i renew my contact on 9 march 2018 at the same time i bought cellphone accessories among others it was glass protector. On 10 march 2018 the glass protector removed from the phone while i was using it. I called the shop on 12 March explaining that am away from your shop i will be available on wednesday to return the glass protector which is poor quality and they agreed with me that the glass protector is not good quality the consultant was assisting he advicsd me to replace it with the travel charger where i explained that i could not replace glass protector by charger while am in need of the glass protector. They demanded box of the glass protector and explained that the time i bought the glass protector they just put it without giving me the cover of the glass protector then he refused to refund me to go and buy the quality glass protector to the other shop. please i need my money back to buy the quality cover. i also interested to cancel my contract with immediate effect since i received such treatment. i will never and ever recommend the vodacom shop to other public and family members.