Poor customer Service

On the 23rd of September I went to Samsung Mall of Africa branch to repair my A50 their technician told me that they didn't have the screen in the store and it's not advisable for me to leave the phone at the shop as it take a day to fix it, and he took my details and promised to call me back before the 29th or as soon as he gets the new screens till today haven't heard anything from him. And a week before the 23rd when I took it for repairs he told me that it would cost R2200 to repair it but a week later on the 23rd the price changed to R2500. All i'm asking for is for good customer service and please teach your employees about treating customers fairly. I would really appreciate positive from you and also the technician to keep his promise.