If your returns were accepted then only the IRS & State would know about your refunds. If you received a letter, hopefully you followed the steps in the letter.
You can checked the IRS website Where's My Refund for your Federal information?
https://www.irs.gov/refunds
If you have a State refund, click on the following link, then click on your State
https://ttlc.intuit.com/community/refund-status/help