110mama, please tell us what's going on.
Did you do a shop? You had to buy something, I take it. Did you turn in the report? Was the report accepted? Are you not getting paid? Did they go bankrupt? Were you supposed to be reimbursed?
I would generically say that if your shop was rejected and that's why you're not being paid, then yes, you can return the item. But I don't know enough about what happened to know if there is a reason why that would not be an appropriate response.
Time to build a bigger bridge.