You can help yourself some by taking screen-shots and other record of the harassment, and reporting it to IMVU staff via the Report Chat function. I recommend taking your own records as a method of verifying should IMVU staff fail to do their job correctly. Third party records are also helpful, someone trustworthy who can witness the harassment and report it. Share this info with your friends. I'm sure TIM will assist you in other ways as well, ways someone such as myself cannot. Good luck and blessed be.
EDIT: PS: I also recommend visiting
this thread. It not only verifies the above method, but also reinforces it with safety tips to keep you from making a mistake and getting warnings yourself.