The Communications Workers of America said that thousands of staff protested in 100 locations including technical and customer care call centres. The company said that the walkout had not affected services.
The memo sent to staff and seen by The Oakland Tribune allegedly said that recent "union activity has caused some of you to make a choice not to serve our customers."
"Given comments I have heard from many of you regarding the importance of providing good customer service, I'm a bit puzzled about why you would leave customers without service we committed we would provide them."
The memo added that "The company doesn't suffer. In fact, these actions help us financially when we don't pay you."
The company declined to comment on the memo.
AT&T is currently in a series of protracted wage negotiations with the CWA union over employment terms that had expired in April.
The union is currently calling for a National Day of Action on June 22nd if the wage negotiations have not been settled.
On the web: The Oakland Tribune - CWA District 9
Posted to: www.cellular-news.com/story/54829.php