Should I withdraw my paper from a journal which even didn't give me the manuscript number after one week?
One week is not an especially long time. You write that you've had previous experience with this publisher and they gave you a manuscript number promptly, but you didn't write if it's the same journal. Different journals can have different workflows - for example I've seen a journal which processed new submissions once a week, i.e. if you're unfortunate enough to submit your manuscript the day after they process new submissions, you won't get a manuscript number until one week later either.

It's up to you whether or not to withdraw, but I'll say that I've never seen an author withdraw after one week. I have however seen authors write to the journal asking about the status after one week. If you're really concerned, I would do that.