Forging the signature on the service card

Iam using gold Nova aquaguard since 3 yrs.Free service was due on 28-1-11 Unfortunately the service was not done but on the service card my signature has been forged which was detected on 26-5-11 while a gentle service man came for the free service. This is from Bhubaneswar the card no is M-728 and a xerox copy of the card is with me. Thus the service centers are cheating.