Correct, you should seek reimbursements. Do not forfeit the funds.
Let's say your tax bracket is 25% and you have $1000 in your dependent care account. You pay for $1000 worth of dependent care. If you send in your dependent care receipts for reimbursement, you get reimbursed $1000, and must pay $250 in income tax, so you net $750. If on the other hand you don't send in the receipts, you forfeit the $1000, and you get reimbursed $0 and pay $0 in tax, so you net $0.
Details of the calculation: Since you are not entitled to the dependent care exclusion, you will have additional taxable income equal to the amount deducted for DCAP minus the amount forfeited. The calculation of the taxable income amount is in part III of form 2441 - on line 12 you enter the amount deducted, and on line 14 you subtract the amount forfeited.
Another way to look at it: if you get reimbursed, you are no worse off than you would have been if you had never enrolled in the dependent care program in the first place. If you forfeit the money, you just lose it, period.
