Extraordinarily rude and patronizing. Refuses to a...

Extraordinarily rude and patronizing. Refuses to acknowledge receipt of any documents I've sent them, continue to call and harrarss me claiming they never got them, but then demand that I pay over $500, before correcting themselves in the next call while never admitting they tried to duplicate the charges. The woman who called me today had me broken down in tears. What happened to decent common courtesy?