You can't get it back. No refunds. Just stop your automatic top-ups and use it up before you cancel your account. Your 50 could have come from automatic top-ups or perhaps from monthly rewards. Eg. You get 5/mo if you referred someone.
Be careful when you upgrade plans.
Eg 1. Lets say you have a 40/month plan that starts on the first of the month. If you decide to upgrade on the 2nd of the month to the 50 plan you will lose the original 40 and then be charged about 48.50 on the 2...
