National Australia Bank's wandering ranking on customer satisfaction remains on the right track, after around a year or more of declines in the Roy Morgan Research Consumer Satisfaction Report.After years of improvements, NAB's ranking relative to its major bank peers drifted from 2015 following fleeting bragging rights as the bank with the highest level of customer satisfaction, among majors.Now 80.3 per cent of NAB's customers tell Roy Morgan they are satisfied, little better than the major banks' average.NAB "showed the biggest improvement in satisfaction in January among the four major banks (up 0.9 percentage points to 80.3 per cent), maintaining its second position and closing the gap on the CBA, which is now only 1.6 per cent points ahead," Norman Morris, industry communications director at Roy Morgan, said."This improvement was due mainly to gains made in mortgage customer satisfaction over the month, up 3.2 percentage points," Morris said.Major banks remain no match for mutual banks in the customer satisfaction stakes, with this monthly measure still led by Greater Bank (95.0 per cent), Heritage Bank (92.3 per cent) and Victorian Teachers Mutual Bank (92.0 per cent).