Al-jannat housing scheme real or fraud, need a background check

Salam,
Today i got an offer call from al-jannat housing scheme karachi office. They offered me 50 % off on the plot value against a coupon that i had and offered me 140 sqft plot in rawalpindi. Not sure if this society is real or fraud? The landline from which they called has a last digit difference from the number mentioned on their web site. Does anyone has some info regarding this marketing company?.