Yeah, I mean it only makes sense. It's about price discrimination - they don't want to give you a discount if you're willing to pay full price, same reason companies send out coupons or mobile app offers. They want to offer discounts only to bargain hunters and those who otherwise wouldn't be able to afford the service because that's where it's worth spending the money for them.

If you're not already, find yourself a local deals site - it can really help you avoid getting screwed over by stuff like this. You can also wind up staying if you're willing to call your current provider back and say "here's what they're offering, beat it or I'm leaving".