Product Registration

I purchased Directory finder from Themeforest a long while ago but never used the theme. Now i am trying to use the theme but i am constantly getting a theme already used error message on my site. I have tried deregistering the purchase code multiple times. I have generated an API but the error persists. On the AI site the theme remains as inactive.

I don’t have a support package but all i want is to be able to use what i paid for?