You don't still have the Acquisition installer? I'm not sure how long Acquisition's support for their paid version lasts for. Your support may have finished which is why you can't access the paid version from the site any more.

What do you mean it just stopped working? Would not connect or would not open?

If you were unable to re-install, it may be due to the Acquisition receipt file. Try removing it from the Receipts folder. ie: main OSX Library -> Receipts, and I guess it will either be called Acquisition.pkg or Install Acquisition.pkg. After removing, try installing again. However this process is usually only needed if downgrading in version, not upgrading.