Bullying at work, don't want to go back

I’m not great at explaining things, but here goes. I’m currently on maternity leave and due to return in January next year. The thought of going back fills me with dread. I work night shifts at a supermarket, primarily stocking shelves, and before I went on leave, I was being bullied. My own team was great, but the online shoppers (those tasked with picking items for online orders) made my lifea nightmare. They act as though they’re the only ones with deadlines, constantly blocking access to shelves and disregarding everyone else. Early in my pregnancy, I had a run-in with one of them. She moved the delivery cage I was using out of my aisle while I was working. All I did was calmly say I needed it there and moved it back. Her response was to shout at me in front of everyone, claiming I was blocking the aisle which I wasn’t. The cage was at the end, out of the way. This was thefirst time I ever went to the store manager, who agreed with me. She got nothing more than a slap on the wrist, but instead of improving, her behavior became worse. She and her sister (who also works the same shift) made it their mission to make my life miserable. They would bang their trolleys into me, knock things off shelves so I’d have to pick them up, and whisper cruel remarks just loud enough for me to hear. The worst incident happened when I was tidying shelves during my pregnancy. One of them deliberately elbowed me in the stomach. It hurt, and I was so upset I spent my entire break crying in the bathroom. Afterward, I called in sick for the next two shifts because I couldn’t face going back. I didn’t report it there were no witnesses, and I didn’t want to seem like I was causing trouble or risk making things worse.Even now, while on maternity leave, the anxiety hasn’t gone away. I’ve been into the store a few times to shop and see my colleagues, but one time she was there and made a snide comment about my baby. It was infuriating and brought everything rushing back. I don’t want to return to work, but I’m struggling to figure out what else I to do.