If you lost your refund check, you should initiate a refund trace:

• Use Where's My Refund, call us at 800-829-1954 and use the automated system, or speak with an agent by calling 800-829-1040 (see telephone assistance for hours of operation).
• However, if you filed a married filing jointly return, you can’t initiate a trace using the automated systems. Download and complete the Form 3911, Taxpayer Statement Regarding RefundPDF or the IRS can send you a Form 3911 to get the replacement process started.

Your claim for a missing refund is processed one of two ways:

• If the check wasn't cashed, you'll receive a replacement check once the original check is canceled.
• If the refund check was cashed, the Bureau of the Fiscal Service (BFS) will provide you with a claim package that includes a copy of the cashed check. Follow the instructions for completing the claim package. BFS will review your claim and the signature on the canceled check before determining whether they can issue you a replacement check. The BFS review can take up to six weeks to complete.

You can use the IRS " Where's My Refund" tool. It will show if the refund was received, approved, or if the refund was sent. Also, at the top of this website there's a direct link to the IRS tool.

https://www.irs.gov/refunds 

Yes, they are taxable. Both federal and state taxes are applicable. 

According to the IRS most clients will receive their refund in 21 days. However, certain credits and deductions that are apart of the PATH ACT can delay this timeline. 

Once you refund is filed, we timestamp it and electronically send it to the IRS. Then they will review it. If everything looks correct the IRS will approve it and began to process the refund if your due one.