The process for cancellation of an OVH VPS is not as simple as it in the case of other VPS providers.
In Linode, for instance, one can simply delete the VPS and this will stop incurring the charges for the VPS.
A similar process is there in the other VPS providers such as Digital Ocean, Vultr and Scaleway.
However, OVH does not have a system by which the customer can himself cancel the VPS.
Automatic suspension and cancellation of OVH VPS
The customer does not need to take any further steps to cancel. When the server expires on the specified date, it will be suspended. After five days of being suspended, the server and along with all the data on it will be deleted.
Obviously, the customer must keep a full back up of the data that he wishes to retain.
OVH does not offer automatic renewal of its services. So, there is no not need to worry about being billed on an ongoing basis.