Bought Pro Plus, Mac doesnt recognize my key

Has anyone else experienced this? I work for a company that pumps out 5-10 macs per day and want to monetize and promote what I've found to be a good product. I also promoted this on over 3000 imaged PCs in a school board. They wouldnt spring for the network edition but I know a good thing when I see one.

Are the licenses bought separately? If so, why? Pro Plus doesnt mean Pro plus plus?

Any help would be appreciated.

so as not to receive any unintentional wrong info, plus the fact you have a Pro license, contacting Piriform support directly, from their web site, would be best.