Sony Ericsson W700i — GPRS COVERAGE

I AM RESIDING AT SHIVAM VIHAR COLONY NEAR SATYA GAS GODAM, ANISABAD PATNA.ALWAYS I AM FACING TROUBLE FOR GPRS COVERAGE PROBLEM.SOME TIMES NO COVERAGE OR VERY WEAK.ABOUT SIX MONTHS AGO THERE IS NO GPRS COVERAGE UP TO 15 DAYS.AFTER SEVERAL COMPLAIN IT HAS BEEN RECTIFIED.SINCE 12.03.2008 AGAIN ARISING THIS PROBLEM."CHECK NETWORK COVERAGE OR DATA, INTERNET SETTINGS" GIVING AS MESSAGE.HOWEVER THE BALANCE IS SUFFICIENT.IN OTHER AREAS OF PATNA IT IS WORKING.PL TAKE CARE ON MY PROBLEM.MY MOBILE NO IS [protected].
ANOTHERTHING IS THAT, NO FACILITY PROVIDED BY AIRTEL TO TALK AT CUST CARE BY MOBILE/PHONE IF ANY PROBLEM PERSIST EXCEPT INFORMING BY MESSAGE.IT SHOULD BE NECESSARY FOR BETTER SERVICES.
i HOPE YOU WILL TAKE CARE ON MY PROBLEM AND SUGGESTION.