Good support — until I asked for a refund
I purchased Sublium in good faith and initially spent considerable time corresponding with their support team about whether the plugin could handle the requirements of an established retail business.
My requirements were hardly unusual: product prices change, Royal Mail shipping rates change, and customers sometimes purchase subscription and non-subscription products together.
During our discussions it became apparent that several things I needed either could not be handled as expected or would require custom code. To their credit, the support staff were initially polite and helpful and referred some of my questions to their product team.
Ultimately, however, I concluded that the plugin was not suitable for my business and requested a refund.
That is where the communication stopped.
My refund request received no response. After waiting, I opened a PayPal claim. PayPal declined it because they found no evidence that the product had been misrepresented — which is not the same issue as whether Sublium should refund a product that proved unsuitable.
After PayPal's decision, I contacted Sublium directly again and asked them to deal with my outstanding refund request.
Again, no response.
Several weeks later I have received neither a reply, an explanation, nor a refund.
I don't leave negative reviews lightly. I would even have accepted the courtesy of a straightforward response telling me that they were refusing the refund and explaining why. Simply ignoring a customer once they ask for their money back is, in my view, unacceptable customer service.
Based on my experience, I cannot recommend Sublium. If you run a WooCommerce retail business, I strongly recommend establishing in writing before purchasing exactly how it will handle changing product prices, changing shipping rates, mixed subscription/non-subscription carts and existing subscriptions — and checking the refund terms very carefully.