Why didn't you just keep that one VPS 4000 if you need one anyway?
And did you cancel the order via their support for the first VPS BEFORE it was provisioned or did you cancel the service at all?
As a business customer, unlike private customers, you usually don't have a right of withdrawal. You'd really have to rely on netcup's goodwill to get them to cancel that first order for you.
I already have my setup ready
1 × VPS 4000 G12 + 2 × VPS 2000 G12.
I have one more VPS 4000 G12 which is no use for me .
I see that netcup have ownership transfer option so I posted my offerings on swap ownership