Nokia India — mobile touchscreen

after breaking my touchscreen of nokia lumia 620 and I got my new touch screen replaced from nokia service centre dilshad garden, delhi and i was charged ORIGINAL TOUCHSCREEN price that was 3000 rupees... but within 15 days the touchsreen was not working properly, it was having some problem...then i told about this to the same nokia service centre, dilshad garden...and they submitted my phone and said to me that i will get my phone within one week...but unfortunately 13 days have gone and i still didn't get my phone...and the people who are working in that service centre they are good at procrastinating... whenever i call them they say " plz come after 2 days, pls come after 3 days...like this" ... I am just like a handicape without my phone literally..and i m REALLY NOT satisfied with the service provided by them i would say...