From a praxeological discourse approach along with theoretical methodology aspects in Social Discourse Interactionism, this contribution aims at reflecting about text linguistic materialization in asymmetric service relationships. Since these relationships are established by actors with preexisting social and praxeological roles, but constantly updated because of the current interaction, we try to some text linguistics formation which can translate these asymmetries in a case study. In order to do so, we collected emails and letters sent between a client and a Portuguese public institution (airplane company), in the end of 2009 and beginning of 2010. The documents analyzed focused on macro act complaining.