I switched from prepaid to postpaid; what happens with my prepaid account?

I just switched from Prepaid to Post paid. 2 questions:

1. I am in the middle of the billing cycle for my prepaid, can I get a refund/credit?
2. I was using automatic top-up. Is that automatically shut off now or do I have to do something? I tried going into my prepaid self-serve, but can no longer access it, understandably.

Thanks.