Working Visa approval timeframe

Hi everyone! I hope all well in here.

I recently got an offer to work in POM. The process started last April 15, 2018, medical exam, red ribbon docs and all other requirements submitted within the same date. I just got an update from the agency last July 13 that my work permit has been approved and waiting for the visa approval. Till now, the work visa hasn't approved yet.

Just really curious, how much time would it take from the date the work permit has been approved up until the approval of the work visa?

It's running almost 4 months now and still haven't done, sometimes it really gets frustrating.

Please help. Appreciate your insights.

Regards to all! Thank you