Premium membership question

If one has purchased premium membership for a period of time, and during that period submits a review worthy of 60 day free premium membership, does the free membership run concurrently with the paid membership or does the free membership begin on the day the paid membership term ends? It seems to me that unless the review based free membership doesn't start until the paid membership ends, (in other words, the 2 memberships run concurrently) this will discourage those who paid for premium membership from submitting reviews during the term of the paid premium membership.OW

all new credits get added on to the end of current service.
not double dipping on our behalf.

also it is 6 weeks, not 60 days for an approved review.