I have a year 2000 dime. This dime has been stamped with both the impressions of a dime and a penny. Both are very visible. It is about the size of a penny. The heads are on the same side, at about a 90 degree angle. the penny head is on top.
Welcome to the post. If you could post a photo that will help a lot. A good desciption also. Does the coin have a reeded edge like a dime? Does it have the color of a dime? Does the reverse of the coin have both impressions also? My first guess would be that this is a forgery. I have come across several denominations lately that have been altered with two denominations. These are pretty good forgeries. There are a few examples of mint made errors like these, but even those coins have suspicious origins. Some feel that the mint employees are creating them in an effort to make money on the side. If you can post a good quality upclose photo, we can go from there.