Sounds like someone is a Delta marketing dream customer...I bet the OP thought we received Triple Bonus miles above and beyond the initial 1.5x's granted for Y/B/M fares. That would get you to the 74,957...
Don't you LOVE how Delta markets these promotions?!!?
OP - FYI, the Delta promo is essentially a doubles miles promo. You'll get double the 1.5x's you normally get for Y/B/M which equates to 3x's the qualification miles (keep in mind the bonus is NOT on banked miles).