[Resolved]  Nokia Lumia 710 — defective phone

Address:

Chennai, Tamil Nadu

i have bought Nokia lumia 710 phone in the month of march 2012 since then i have so much of problems with the phone.
problems are,

1. unable to purchase applications through phone and internet
2. sometimes unable to send text and mms messages
3. sometimes people are unable to contact me
4. and today (11.4.2012) i am not able to contact some of them
5. in the beginning i was unable to update my phone software (not now)

so to sort it out i approached nokia care but there they took the hand set and asked me to come the next day this happened about 4 to 5 times each time there is a new problem so any one has an answer for this ? i suspect the phone itself is defective!!