[Resolved]  Motorola Mobile Phone Motoyuva W270 — mobile not functioning properly

I had purchased motorola mobile w270 from RPG Cellucom India pvt Ltd(TIN NO [protected]) located at Spencer's super, salimar building, MG Road Hazratganj Lucknow on 21/06/08 vide Challan no 304 dated 21/6/08 for Rs 3215/-.The mobile stops while talking and automatically switches off.The same was shown at a authorised servicecentre at Allahabad where I am residing which was repaired but again it is showing the same defect and in addition the stored numbers are also disappearing.It is still in the gurantee period.I am not sure whether it will function properly again and most of the time is spent in giving and taking to the repair shop.Kindly advice how to get the set changed with the new one or get my money back