Stardollars get locked when membership runs out!

Hey everyone, I thought this would be something important to share. If you still have many Stardollars left and your membership is about to expire, don't forget to use them! To bad for me, I wasn't keeping track of when my membership expired, and I was sad to log in and see that my Stardollars had been locked. I knew Stardollars were Superstar currency, but for some reason I didn't expect for them to be locked. After that you have 2 options, the first would be to keep your Stardollars in case you decide to become a Superstar again, or trade your dollars in for coins. You will receive 10 Starcoins for every 1 Stardollar.

Do you think this is fair?
That we paid for our Stardollars but if we do not use them in a certain amount of days they are taken away?
-twilightgirl995