Poor service and attitude

I got a iPhone X cover as a gift and went to the Istore in Sandton and was advised that it is over 10 days and I cannot return this , it is in its original packaging. We have the same problem with the screen protector at the time of buying it they said it has a years guarantee, again n they refused to change . We are a family of 9 people and we all have IPhones, MacAir; IPads , all of which was purchased at the Istore . Extremely disappointed with attitude and poor client service from the store manager .