ian_stagib ...it's unfortunate that you have encountered what actually is a commonly occuring issue, particularly with online purchases.
Any and all such purchases NEED the purchaser to NOT rely on the vendor maintaining/retaining copies of a customer's purchases. The correct process is that once you have made a purchase you download AND RETAIN copies of the product AND its relevant activations/serials, particularly if such purchase is via a 'subscription' basis which it is intended [at some time] not to continue.
The responsibility is yours, just as it is mine - with my purchases.
The definition of what an Object Desktop Subscription entails is well stated, on the link above [product description], on the Stardock Official Forums, and, if subscribing to Stardock's Newsletter /email notifications you'd likely be reminded of, and conversant with exactly that.
Your options are one of two.
Resubscribe AND access your software versions/updates,
Approach Stardock via firstname.lastname@example.org and request special consideration in your particular case.
I certainly have had similar situations with third party products over the years. Sometimes account expiry/renewal deadlines are simply missed. It happens....