Abu dhabi employment visa-inexplicable delay

Hey everyone,

i have a question please, a few actually, if anyone has been through the same situation as i am currently, it would be useful for us to share our experiences. I'll start with the main question first then share some clarifications below. Can it happen that an employer extends an official job offer (basically a detailed contract meeting the criteria of MOHRE/formal/on letterhead) and then for some reason stalls the following work permit/visa procedures with the purpose of ultimate revocation of the offer? by just saying that the visa application was denied after some time for example...

details and context of the situation:

-application for a position on company's website/video chat interviews/job offer received some time later
-offer accepted and contract signed (only by myself, i don't have a copy of the contract with both my and my employer's signatures on it... is that in accordance with certain laws in abu dhabi? What does it mean for the legality and validity of the contract? Why hasn't the contract been signed by the employer?)
-after that i was asked to send a copy of my passport, a photo, academic credentials (college degree) and to complete security forms (issued by the free zone where the company is headquartered, abu dhabi) and also to fill in an employment visa application form

Since then, more than a month ago, i received no informative feedback and absolutely no details about what's going on and why the work permit approval and visa application are taking so long. I was informed that they haven't applied yet for the visa after all this time, which made this whole situation seem suspicious to me...all i'm told when i call is it's a process and that i will be informed when it's done. my questions to HR on the phone regarding possible waiting time were dodged multiple times, and my emails to them and calls not answered   
   

in this situation, especially when they say they haven't even applied for the visa yet, i found my self left with only one possible scenario, which is they are probably not applying for the employment visa and they are trying to subtly back away from the offer for some internal reason...or is this only the stress of waiting putting imaginary thoughts in my head?? I don't know...

what do you think guys? Has anyone been through or heard of an experience like this? Any HR professionals here? Your thoughts and suggestions will be so appreciated