I wouldn't use a "Parents with Prams" spot unless I was using the pram. I pretty much always use it when shopping anyway. The "Coles Baby Club" (think that's what they are called) spots are different as it doesn't specify pram.

I wouldn't actually be upset about it if someone without a pram but with a young child was using one. I hate it when people use them who have no capsule or car seat in their car. Clearly they don't have a young child in the car.