The ranked coins

I have a problem with the coins in the competitive mode of Overwatch in which all the time I spend playing in ranking to get the coins and buy a golden weapon are in vain due to the change of the red and white coins, causing me to end up with 2900 white competitive coins I won’t be able to use them until next year. The truth is that it makes me want to play the game knowing that the effort was of no use to me and it would be nice if I could at least buy white coins with the red ones or if they gave me the missing white coins for the 3000