Once you apply for services your support order must be paid through the SCU, and you cannot accept direct payments from the non-custodial parent, nor can the two parties informally agree to change the amount of the support order.
If the non-custodial parent pays you directly, the non-custodial parent should file a modification petition through the Department of Probation. This petition will be heard in Family Court. The non-custodial parent would ask in the petition to have the direct payment credited to the account.