The IRS have unfortunately been experiencing delays to various circumstances and it can take them up to 12 months to process your FICA refund claim and issue the refund that you're due to.
If your Federal tax return has been completely processed by the IRS and your FICA refund claim was successfully mailed to the IRS, we'd recommend you to wait at least 5-6 months before requesting an update from the IRS.
Info: Click here to find out how to check the status of your FICA refund claim.