It's too late for you to 'doctor' your CV... The fact is you have now accumulated experience at the poly albeit on a low pay... You'll still be disadvantage by your low pay unless you have skills and credentials which no other candidate has. By the way, omitting your master's degree from your cv is equivalent to lying. If you are ever found out, you'll be fired. And word will spread, that'll jeopardize your other job opportunities. Best to sell your capabilities. Do your research on your job market and move on if you are really not happy with the present.