AIBU to remind people not to reject your allocated school, even if you hate it?
You should accept & put name on wait lists for other schools.
You could try appealing especially if you think an error was made, but if it is an Infant Class Size appeal they are only accepted in very limited circumstances.
The only reasons to reject are if you will be going independent instead or home schooling for as long as necessary (e.g. the whole of infants at least).
Once you have rejected the LA are under no obligation to find you another place.