This is better explained on this thread. It is always hard to argue this as ultimately on our end all we see is the line you placed it at, and it’s impossible for us to completely judge how fast this happened or whether it was the same as a bet you made the opposite way.
Ultimately the way the lines work ‘is a security measure that as a company was implemented to protect ourselves from those who would look to exploit lines or take advantage.’ for instance from players that are live at games and have access to quicker information than even we do.
Note that ultimately lines change very quickly and go get updated in your betslip faster than the actual line onsite. I know it is slightly unfortunate but if you pressed the button after it had already changed then this would be an accepted bet. I get that lines are changing quickly and this can result in getting a line you didn’t want, but it isn’t really something we can cancel or refund either.