Happen what bro ? Biar habis cerita dulu, ini potong stim je. 😊

I dont know what transpired but if there is a Battery Conductance & Electrical System Test done and if you can share that info here, it would surely help. Kalau malu, send to me je la.

Let me go point by point.

1) my car start every week for 20 mins,
- does it mean, you just start the engine and let it run at idle speed for 20 mins aka no actual driving? At Idle speed, your alternator is just pumping small Amps to the battery.
- Usually I prefer to charge my battery first partially first, then only start driving. Not just leave it idle for 20 mins. That's if you have a charger. This to minimise the "Depth of Discharge"
Its not wrong for us (SOP related) to drive out as so long don't exceed 10KM.

Actual driving allows your engine to drive the alternator at 2000-3000RPM, more amps = better charging.

2) bateriku customer service told me if car not start 1-3 days it is going to happen
- Previously when I didn't had my charger, one of my car (Exora) , was left without moving for 2 weeks. Thank god, it still started right up, and drove like normal. Since then I invested in a charger. That way I don't need to drive just to charge. Its charged up and ready to use.

3) even after jump start it doesnt charge back.
- Very hard to say without knowing whats was the last voltage read out and without battery tester to test the battery condition. You still need to tell how you charge it back - is it by idling the engine alone.

Silly me, I forgot in your situation, since your battery died in less than a year right, proceed to claim for warranty. By the way, what is the brand of the dead battery ?

Rubbish.
This is not Genting or some cold winter country weather.
Even Genting goes right down to 20C still the car can start.

Whether you park at basement or I park in my car porch, ambient temperature doesn't affect vastly.
Its only if your car has parasitic battery drain, then it's an issue. Just like Roman Catholic also mentioned earlier.
Parasitic drain is when an accessory in your car drains excessively even when the ignition is off.

All you need is a clamp volt meter and some technique to check for that

Gawd, is this how Bateriku techs scam their way to non knowledgeable customers , in selling their batteries