Just diagnosed, how long do meds take to work?

If Gliclazide isn't pulling those numbers down in 2 weeks, I'd ask the doctor to check out for sure if you are T1 or T2, especially since you are not overweight. Have you lost any weight recently?
I would certainly expect 1500mg Metformin and 40mg gliclazide to work in 2 weeks.
are you certain your carbs are low? are some sneaking in somewhere?
I have been diagnosed nearly 8 years and use 2 x 500 mg Metformin and tight diet. My numbers are in the 4s and low 5s. If I have a bad day, I can get them back in a single day., without increasing medication.
Do you take exercise? I find a GOOD walk every day helps.[ at least an hour, which should be about 3 miles at normal speed]
Hana

It's very early days in your treatment..

It can take a month for metformin to start to work fully, as meforming has to build up in the system first... Glilazide increases the production of insulin, so in theory should have a very quick effect..

Even though as a T2 you will have insulin residence, the residence at the moment will be increased by your elvated blood glucose (this happens with T1's who may require a larger dose of insulin when they have levels, i.e if my blood glucose goes above 12mmol/l a rarity for me, I need 1.1 units of insulin to drop my BG by a mmol/l, where as anything under this 1 unit of insulin will drop my Blood glucose by 7 mmol/l's)

Add to this the need to continue to eat your medication is working on both the food you are eating, and your underlying blood glucose level, so can feel like it's chipping away rather than turning them around over night..

A quick reduction and/or return to normal blood glucose levels when dignosed isn't the wisest ideas, your body would have got used to having higher glucose levels, lowering them too quick at this point, makes the individual feel a lot worse, they can experience phamtom hypo's etc, also it can increase the risk of damaging the eyes causing problems...

But speak to your diabetic nurse about all this and your worries ect.. As she can take a lot at your results decide if more medication at this stage might be appropiate or explain the time scale they are looking at to return you blood sugar back to normal ranges..