(b) Interest shall be allowed and paid as follows:

1. (1) in the case of a credit, from the date of the overpayment to the due date of the amount against which the credit is taken;
2. (2) in the case of a refund, from the date of the overpayment to a date, as determined by the department, preceding the date of the refund check by not more than 30 days, whether or not the refund check is accepted by the taxpayer after tender of the check to the taxpayer; the acceptance of the refund check does not affect the right of the taxpayer to claim an additional overpayment and interest on the overpayment.