This happened to me as well. I made a reservation for this summer a few days before the March 6th cutoff for the devaluation - and when I made the reservation I was indeed given the lower pre-devaluation rate. But when I recently checked the reservation, it showed the higher post-devaluation rate.

Unfortunately, in my case, a call did not resolve the issue. When I called, the agent told me that from his end, it looked like I made the reservation on March 6th (which would be too late). I know this is not correct, but I have no way to prove this. I am wondering if the system somehow re-booked the reservation at the higher rate, with the date for when the higher rate went into effect. Has anyone else experienced this? And any suggestions on what if anything I can do about it?