When you file a claim for a Child & Elderly Care FSA expense, only the amount of funds available in your account at the time can be reimbursed. If your account's balance was less than the expense, you'll only be reimbursed for the balance in your account. The remainder will reimbursed to you as your account balance increases. For example, if you file a claim for $1000, but your account currently has only $500, you'll only be reimbursed $500 initially, until your account's balance increases.
If you believe there has been an issue with your claim, contact Support.