Bad Service / Invasion of property with permission

Visited Vodacom Randburg mall today and was given the most bad service ever. Walked in to store and greeted and was assisted. I asked for a glass screen protector for my Hauwei P8 Lite 2017 and was told they have in stock. The casher by the name of Rita cashed up the item and was billed R169.00.i asked if anyone can assist with putting on for me they said yes. I waited about 15-20min as they took my phone to the back office. After the waiting Rita returns and says to me the exact words 'Please can I have your slip. I said ok and hand it to her 'she gives back my money and says they don't have the cover the only cover they have is white. Not once was sympathetic or apologetic. She hands me my phone and when I looked at my phone I see my Original screen cover was removed. I was not asked if it can be removed they just did it,I took my phone and walked out the store. Upset as hell. I was treated as if they were doing me a favour yet I was paying. Not expectable. While sitting there I decided to buy a sim card and rica it for my son to use Vodacom all was done and payed for the new sim,but changed my mind after the service I was given il rather use another network.UNHAPPY CUSTOMER