Turnaround Time sucks promises and promises with no delivery

Phone handed in at Samsung repair Centre on 8 January 18 and was told maximum repair time is 7 days. It was just to replace a screen that was still under warranty. Follow up on follow ups with no joy . Today 12 Feb. still no joy and still waiting for a part. I am just so fed up and despondent with the delays. I have 4 messages for the Manager to call me but also no joy. Why would anyone want to buy a Samsung device if this is the kind of service you get. This is definitely the last Samsung for me. Can anyone in Samsung please tell what me what the hell is going on with such a huge delay. Why must I follow up all the time