HOLY SMOKES!!! It works!!!! Out of desperation I googled “why can’t I find my wifi network on my iPhone?” The top result was a forum which suggested I just try removing the case. To me it seemed like a ludicrous idea but after having fiddled with my phone the past two days I decided to give it a shot. And just like that, I could detect the office wifi signal which I haven’t been able to for days. It beats me why wifi signals which can pass through walls can be blocked by a plastic case. Maybe someone familiar with the physics of wifi waves can explain it? Lead in the plastic or paints used on the plastic case maybe? Maybe because the iPhone case I bought was mirrorized?
Moral of the story: Sometimes what are to you the silliest solutions to a problem are the right ones.