I am taking janumet (sitagliptin and metformin) 50/1000 twice in a day still my sugar level is 220 any better tablet you can advice me please?

Sorry, no. I'm sure you've heard the advice: "Don't change your medication except on the advice of your physician." We are NOT your physician and it would be unprofessional for us to give you such specific advice. Talk to your doctor about diabetes medications and other ways (such as diet & exercise) you can control your blood sugar. Best wishes.
Additional med. depending on how long you have been on it may need another medication added. I give my patients 3 months on the medication to see if it is effective. If not, then can add another medication. Which one is a discussion you should have with your doctor as there are MANY choices. hope this was helpful. Best of luck. Dr R.