Where does it leak from?
I used conveens for several months, without issue once I had overcome the issues.
Without knowing exactly what your issue is, I will cover off the problems I had early on, and hope this covers your problem. If not ask away.
1. size and fitting problems. When I was measured at the hospital, the ward was very warm. Very warm environment leads to an enlarged penis, leads to a larger size conveen than you might need at normal room temperatures.
Solution = smaller size conveen for normal temperature use. In addition I used insulating tape to secure the conveen to my body. Also shave the base of your penis to enable as good a seal as possible. This also means that removal of the conveen is easier and pulls less hair out.
2. Leaking at the base? Leaking where it joins the bag tube? Tugging?
Solution = convenes come with 2 "trunk" lengths, the nozzle bit at the end. If your conveen is tugging at the tube, get ones with a longer tube. Wear it as high and you can on your leg, use additional ties to secure the bag so that the bag does not ride down with use.
If you are more specific with your problem, we may be able to offer a more bespoke solution for you to try?
dave (a fan of the correctly used conveen)