No response from Journal even after 3 Months of submission
This situation is indeed not normal, and it sounds like you've hit your tolerance limit with this particular journal.  You've done your best to communicate, and now your paper has been withdrawn even if the journal has not recognized this fact.

Why do I say this?  The fact is, that until you've signed over a transfer of copyright to a journal, the paper is not theirs.  In the typical Elsevier publication process, you don't sign that transfer until much later, so your manuscript is entirely yours right now, not the journal's.  As such, you've withdrawn it and should do whatever you wish with it at this point (i.e., submit it to a better journal).

Now, it's possible that this problematic journal will do something else strange at this point, like send it out to reviewers despite the fact that you've withdrawn it.  If that happens, though it is not your problem.  If that happens and you find out about it, then hey, they've actually communicated with you, and you have another excellent opportunity to remind them that you have withdrawn your paper.

The only possible ethical problem is if they send it out for review, you get the reviews, and then you reverse your decision to withdraw the paper: then you would be changing your situation to having effectively done a parallel submission (to this journal and wherever you go next), which is almost always considered improper.  Stick by your decision to withdraw, and you are fine.