Shocking service

Upgraded my cell phone. Requested the service provider to provide me with a cellphone over and screen protector. The service provided suggested a cover and protector and provided the phone with the additional accessories. After a couple of days the screen protector broke. Vodacom said they can replace the protectorbut that the type of phone case they recommended will keep on breaking the screen protector and I have to get another phone case. They are refusing to take responsibility for their mistake and now I have to pay for their mistake. The people in the store are ******** and rude regarding my request for an amicable solution.