it's mall's responsibility if the floor is wet or there are obstacles that cause the child to slip or get hurt. But it's YOUR RESPONSIBLITY to make sure that children does not climb on anything unattended. Instead of thinking about how much money you can get to the mall, take your child to see a doc asap.
Besides, isn't it COMMON SENSE that flower pots are not used as weigh supports? Why should there be signs??