I'm not sure what your beef is, but I'm just pointing out that it's probably not due to Changi Mobile as many here so quickly blamed if you follow through.
I am not saying that any telco has extra filters, but if you scroll back a few pages and read, the implication is that many were claiming that other telcos have filters, but Changi did not. My post was anecdotal, but to point out the experience of receiving spam calls is no diferent no matter what the telco is. It's on the spammers, not the telcos.
So I believe you've completely missed the point of my post, which was a made as a refutation of the idea that "
Changi Mobile = spam. Port out = automatic no spam" - I am defending Changi Mobile here with that false idea that many users here claim is what they are doing. Besides, who would posit a negative experience after porting as a form of promotion? It makes no sense.
And your first allegation is patently false. I don't work for any telco. I work in the social services sector.

That's why I move around a lot because clients/patients across in various parts of the island.