Repair - Damaged done by Apple

Around end of June I booked in my cellphone at IStore Mall of Africa ,The phone was still under warranty and the email trail which can be supp**** to further investigation shows that Istore did no communication only said the phone is being repaired and is in the que for assessments . After collecting my device the did no repairs on the phone saying the phone scree below at charging point is stripped? This couldnt be the case as the phone has never been in for ANY repairs. Istore just refused to look at the phone and confirm that no internal tampering was done within the device. They damaged my ***** now refuses to further asses the phone amd confirm that their was no internal work done on my iphone which has due to Istore incompetence is out of warranty

Repair number - R431314 - MA36450