Nokia — not retuning mobile phone even after almost 40 days

i have given my mobile nokia 3110 classic on 22nd of august and person at
nokia care centre UNIVERSAL
2, [censored]AVAMDAN COMPLEX,
OPP.BHAVANA FLAT,
COLLEGE ROAD,
NADIAD.
HE SAID IT WILL BE REPAIRED IN 20 DAYS AS THERE IS PROBLEM IN IC WE WILL SEND IT TO DELHI SO I AGREED.
THEN STARTED MANY VISITS OF CARE CENTRE SOME TIMES THEY SAY IT WILL TAKE A WEEK OR MORE
SOME TIMES THEY SAY YOUR PHONE IS TAMPERED BUT I HAVE NEVER REPAIRED OR EVEN OPENED IT BY PRIVATES MOBILE REPAIRES
NOW THEY IT WAS BY MISTAKE AND IT WILL TAKE SOME MORE TIME
I DONT KNOW ANY WAY HOW I CAN GET MY MOBILE BACK

RATHER THAN CUSTOMER CARE CENRE THEY HAVE PROVED TO BE CUSTOMERS HARRASMENT CENTRE AS FAR AS I AM CONCERNED