After using 
metformin thrice daily still Ur sugar levels are not under control .
firstly to get a sugar control or to maintain it .the three important aspects are : 
1.Diet 
2.Exercise 
3.Medicines 
firstly diet - it should be taken at proper timing .
                 .I.e breakfast  between 8 to 9am 
                       lunch  between 12.30 to 1.30 pm
                       snacks between 4.00 to 5.00 pm
                       dinner between.  8.00 to 9.00 pm.
totally stop  sweets,s ugar,potato,banana,mango,sithapal,sapota,grapes
Exercise   - walking 20 min per day at least 
medicines - stop metformin 
                    1. take a combination of metformin 500 mg + glimiperide 2 mg twice daily  5 min before breakfast and 5 min before dinner
2.take one tab.metformin 500 mg  sustained release( sr )  20 min after lunch 
get testing done after 2 weeks