Thank you for your inquiry. You can actually download JomSocial 3.1 by just downloading it from your account page OR by using the iJoomla installer. To download it from your account page, navigate to My Account > My Downloads and click on the green 'Download' button. To install it using the iJoomla installer, go to your backend > Component > iJoomla installer. From there, key in your license number in the 'JomSocial Professional' license # field and click on 'Update'.
Would you be kind enough to try out the solution that I've outlined above? Let me know if the problem persists.
We have not received any response back from you in over 7 days, and would like to know if you consider this issue to be resolved. If you have any further questions, simply reply to this post.