<prompt> Translate the following text to EnglishUanachama unaweka wajibu wa kudumisha viwango vya ubora na huduma, na hutoa wateja wasio na kuridhika na njia inayotambuliwa rasmi ya kurekebisha malalamiko; nambari ya kupiga ni Tel.  <response>: Membership imposes an obligation to maintain standards of both quality and service, and provides dissatisfied customers with an officially recognized channel for redressing complaints; the number to call is Tel. 2508 1234. 