The game studio confirmed the offer appears to players who don't have a King account but it's available just for new players below level 100, unfortunately.
I have a King Account and am way above level 100. I thought my Facebook and King accounts were already linked but the free Piggy Bank offer made me think maybe they're not linked? Regardless, if the offer isn't real, it's a cruel joke/trick.
I noticed a drop in Gold Bars from the Piggy Bank and refuse to make any additional purchases. I cannot believe the 20 bar decrease--from 100 to 80. What a rip-off! Greed will cause a significant loss of support from valued customers.