I am leaving my current job. In this role I have done a lot of design work for the company, all which I designed myself. I wasn't employed to do the design work, it was something I did in addition to my role and because of my design background I spent a lot of time on promotional materials for the business. I didn't mind putting in the extra effort at the time and lots of people commented on how great they looked but soon after the company weren't particularly good to me, negative director etc and I have found another job.
The company are now asking for my original documents I used to create the designs so they can edit them for their future work. I feel a bit uneasy doing this and feel why should they benefit from my designs when I won't be in the role and they haven't paid me any extra for these particular designs or been a very good employer. Could I just say no? Or ask them to reference me if they use my designs? The thing is I may be working with them again in some context (through my new company) so don't want to burn bridges entirely but also uncomfortable with them using my design work going forward. How should I approach this?