randomness and chances can never bring a sophisticated beings to existence, such as the human beings.
Not even if perchance God wanted it so? Because maybe he did. I don't think so, but I can't honestly say that it categorically did not happen either.
How can anyone truly know whether there is a God who for whatever reason makes use of randomness and chances? There is certainly no evidence against it, or at least I can't think of any.
We use math and science to develop things, randomness and chances can't develop sophisticated machines,
That is not really all that clear. Nature does have a knack for developing impressive spontaneous patterns, and it is very possible that life itself developed in that way.
You are of course very free to disagree, as well as to believe that there is a divine will acting there. Many people do and it is at the very least difficult to challenge such a perception.
also things around us work in a scientific way which means a designer is behind it ?
That, IMO, is an open question, and one that can only be answered in a personal way, according to each one's vocation. There is no clear "true for everyone" answer.