@dokidoki—
In what order were these chapters presented in the
tankobon? If they were uploaded in a different order, then you've got a solid case for persuading an administrator to reorganize things. (And, in the case of another manga, I got an administrator to do just that.) But, if they were uploaded in the order in which they were published, then, regardless of arcs, the uploader did nothing wrong; your argument would be with the
mangaka or with the publisher.
As I read this series, I
did notice one or two cases of a pair chapters being combined into one upload. Unfortunately, I don't remember which uploads those were, and I don't really want to search them out.