How do I adjust my credits to the correct amount ( showing far too much), when the 2015 installment amount appears to be correct?

I entered (correctly) that I have paid $14,974.00 in installment payments to the CRA for 2015. This is ALL of the tax I have paid so far. Somehow, however, my credits are showing $29,970.75. I was not required to pay quarterly installments and wonder if perhaps the software is assuming I made more payments than the two last year. How do I adjust my credits to the correct amount ($14, 974.00) as this is my credits--there has been no other money paid.