Engineering degree course has a certain time years only to complete the backlogs, so its better to clear the backlogs even though its tough. Good you have completed the 4 years of education and obtained the Course completion certificate, if this is possible, its also possible to complete the backlogs. It will not be tough if you just have to focus a little more in education to obtain a boost in your career. Its not that simple to obtain a career with only course completion certificate, even though still you have achieved to a good heights in your carrier. Try solving the backlogs and once you obtained the Degree certificate( provisional certificate) that will boost your salary package.
Stay in the job you are now, and try to give some time for study for your engineering course, manage the time, place of study obtain a good marks in the backlogs, that will keep you in peace of mind while working. Also obtain an M.B.A in Banking or finance, stay in the current job. This M.B.A will boost your package to a new heights. Staying in one career, with years of experience being as an expert in field will make your designation to a new heights too.
Take time to study, use your efforts, Time management skills, enthusiasm to complete the backlogs. That will make you more happy that your are now. This will help you to get good job in the same field of banking domain in any other companies with excellent package.