Your feelings are understandable , but a copy of this complaint should be available for you to see in the nursery , for you to form your own judgement , you must bare in mind also , some times complaints are made with the wrong intentions , sometimes made when people are disgruntled about finance believe it or not ! which can be a shame.
i would recommend visiting the nursery again and discussing your concerns , they will more than likely expecting some responce from parents of this nature , good luck i hope you find a place ou are happy with :)