Instruct: Classify Amazon reviews into positive or negative sentiment
Query: forget about customer service--there isn't any

I purchased two of these monitors about six months ago. One works fine. The other flickers occasionally and is not quite as bright as the one that works fine.I don't know whether there is a problem or not.I do know it has been impossible to get through on the phone to customer service. Furthermore, they do not seem to return phone calls in spite of their outgoing message which invites a message and indicates they will do so.It's an unnecessary aggravation.