LG
WRONG IMEI NUMBER

I purchased a LG mobile phone model number C 2600 from an authrised LG mobile showroom named Defence Electronics, Bhati Circle, Ratanada, Jodhpur vide invoice no. 03461 dated 22/10.On 14 Nov I received a message from my service provider (Reliance) that my phone has an invalid IMEI number and when I checked for first time I noticed that the IMEI number printed behind my phone is different from the IMEI number showing by typing *#06# on the phone. I haven't changed my phone software or neither i haven't done any phone service after buying this phone. The service provider's says that I can't use this phone further because this phone does not contain a valid IMEI number. The customer care executive of my service provider says that they notice my phone's mistake now only and they can't provide my phone any network further. So what should I do to correct my phones mistaked IMEI number.