KLM DOESNT CARE ABOUT THEIR CUSTOMERS!!!

My daughter wants to spend an extra day or 2 with her daughter (she hasn't seen them for 3 months) and I found a flight on their website cheaper than what she paid, so we thought we could just pay for the flight change. But NO, they dont offer that price to an existing customer only if you are booking a new ticket, so only new customers get the cheap price. Shame on you KLM!!!! A mother cannot spend extra time with her daughter and she wont see her for another 3 months! SICKENING.