If the customer purchased a SOLIDWORKS license directly by using the SOLIDWORKS Online Store they were charged directly by Dassault Systemes and therefore need to cancel through DS, not DMD/VIAS3D. 

To cancel your auto-renewal:

1. Go to your 3DExperience Account
   
1. It is HIGHLY suggested to download any files you have saved on the cloud platform before or immediately after canceling. You may lose access to your data as stated in Dassault Systèmes Service Level Agreement. While we try to help our customers recover their files, as a third party, we are limited in our abilities to recover data from your cloud storage up to 7 days after you cancel your online subscription. 
2. Click on the "Subscriptions" tab
3. Click on "Manage on your Subscriptions"
4. Click on "Stop renewal" 
   

To cancel your Online Store Purchase:

 

1. Go to your 3DExperience Account
   
1. It is HIGHLY suggested to download any files you have saved on the cloud platform before or immediately after canceling. You may lose access to your data as stated in Dassault Systèmes Service Level Agreement. While we try to help our customers recover their files, as a third party, we are limited in our abilities to recover data from your cloud storage up to 7 days after you cancel your online subscription. 
2. Click on the "Orders" tab
3. Click on "Cancel" button in the bottom left corner
   
4. Enter the reason for cancellation in the pop up box and press Next
   
5. Click "Confirm" in the final pop up box to complete the order cancellation
   

** According to the Refunds & Cancellations policies for the Online Store a customer can cancel eligible orders up to 15 days after purchase. This excludes: renewals, monthly subscriptions, trial offers.

If a customer is unable to cancel their order they will see this on their "Orders" page on the bottom left corner:

If you still experience issues cancelling your subscription use this form to send a message directly to Dassault Systems Online Store Team:  https://www.3ds.com/online-store/support-form/