Is it possible to extend wireless signal without making new ap's?

At the moment i have 3 routers across the house, each acting as a wifi access point.

My problem comes to when i use my phone or laptop, it connect to a random access point doesn't matter of the signal.

Is it possible to combine 3 routers as one access point. So that i would connect to one access instead of 1of 3 access points, that would be a strong wifi signal no matter when i am in the house. Something similar to what bit malls or stores have.

I have looked at wifi repeaters, but they just repeat the wifi and make new access point

Sort of, you should select one as your router (that will provide DHCP server) and the other two will just act as APs with same SSID, but different radio channels from the other two, and have static addresses assigned on the router outside its DHCP address assignment range. That way your devices will connect to the strongest signal and you will have seamless roaming over your coverage area.

Agreed, avoid repeaters, they reduce your bandwidth.