Worse upgrade ever

Horrible went to upgrade a phone on Saturday afternoon and had problems from the get go as the manager said is was a (obf) out of box failure the phone started freezing up the staff said it is a normal thing they told one and another to ssshhhhh about something couldn't clearly make out what they said to each other i had made some payments for a couple of things in the store and haven't received any proof of purchase no slips or anything to show that I have purchase items. Sunday morning i went back then there was an excuse of the manager is in church and no one could help me at the time