going to the immigration is a pain in the ass and costly, either do an e-visa or if you will stay close to a land border cross to a neighbouring country at the end of your visa and come back to get 30 days again.
Visa "exempt" or "waiver" are usually used as synonyms....! Since you don't..., what's the difference?? I've certainly never heard of this one: "Visa waiver is 30 days. You cannot extend this. "
"There was never any mention that it would be extended." That is clearly wrong ! The usual MSM made headlines like: government mulls extension etc..., but apparently it did not get approved. !
P.B. is a pain..., they don't allow visa runs / bounce..., but it's unclear how long you have to stay... So was this you experience LATELY..., 1 night was enough ?