D-Bat Avondale

I went to the location to use a coupon for 45 free swings. The gentleman said I could not use it anymore. He took the coupon and kept it. He would not honor it. This is false advertisement. He stated it was only good for when they opened.
The coupon clearly states "redeem this coupon for 45 free swings".
There is no expiration date printed. Nor any directions when to use it by, or how long it is good for.