You can find exchanges that offer free listings here:
https://bitcointalk.org/index.php?topic=5079048.0However, why the hell are you guys still not interested in just leaving this project already? Rhett has used ZClassic several times before for pump and dumps through scam forks, and he'll use ZCL again for the very same purpose when the right (bullish) time comes.
P.S. Bittrex doesn't just de-list because of "low-volume"; they must have seen the lack of development in the project. Even I requested them in the past few months to de-list ZCL, because of a number of reasons.