This is pretty ridiculous to let us collect currency until the very last day of the event (and a bit after with the extra Box Of Spells), and then remove the option to redeem our rewards. We put in a lot of effort collecting these things, but can't do anything with it. A lot of us waited until the event ended because the redemption period is much later than that and we did not want to purchase duplicate tiles.
Please reconsider your decision of removing the transmutations.