In the press releases from 2016 and 2017 oversubscription meant they raised a greater amount of cash then the amount in the offering announcement. This year's offering was the largest in dollar terms and also the lowest price compared to the last two offerings( although the warrants were half). It looks like the office may have meant they were fully subscribed already when you made your request and weren't going to increase it any further. Their use of the word oversubscription is not consistent with their press releases.