Dryer will not turn off-keeps running

Hi there, Thanks so much for reaching out about this. I can certainly understand the concern with having a dryer that shuts off when it's supposed to. The first thing I recommend is to follow the steps in the link below. It has detailed information on what to check if the dryer won't stop spinning. 

https://www.samsung.com/us/support/troubleshooting/TSG01001990/

Once these steps are completed, if the dryer still won't shut off, it will require service. There are a few options here we can take based on your warranty status. 
If you’re in the one-year manufacturer’s warranty, please gather together the full model and serial number of your unit, and have ready your name, street address, 2 phone numbers (Best contact, alternative number), email, and place of purchase. Provide this information to an agent, in one of the following options below:
1.) Reach out to a Moderator directly, by selecting our name and the message option. When messaging please use a link to this thread in addition to the info above.
2.) Reach out to us on Facebook or Twitter. Please provide the same info as above, as well as the link to your thread.
3.) You can also contact 1-800-726-7864, if you’d like to speak with a live agent about this situation.
4.) Last, if you wish to speak with a live agent and don’t want to call in, you can reach out to our Live Chat team. 
If you’re out of the one-year manufacturer’s warranty: 
1. You can utilize this link to locate an authorized service center in your area to obtain estimates for repairs: http://www.Samsung.com/us/support/service/location or reach out to any local repair shop.
2. The other option, would be a replacement of the unit. Samsung.com offers amazing deals on different models that may be to your liking, check out those deals here: https://www.samsung.com/us/dryers/