Unfortunately the IRS does not provide an online tracking option for FICA refunds. Their only online tracking tool will show the status of the Federal tax refund: https://sa.www4.irs.gov/wmr/
However, you can call the IRS and request an update on your FICA refund here.
Important: Please note that the IRS processes FICA refund claims rather slowly. It can take up to 12 months for one's FICA claim to be processed as delays are quite common.