Place it right after the bold claim in your edit, following No No Wait Wait and before Oh My God Wow, so the claim, the refusal and the reaction follow in that order.
About this sound
This is a short Arabic spoken reaction lasting about five seconds, built around the oath 'wallah' and a blunt claim that someone will get in. It feels emphatic and incredulous, like a firm answer to a doubtful claim, with the speaker insisting the entry will happen despite the scepticism around them.