OK, but I'm 10 years into a similar situation... so....
he picks up 1/10 calls wasn't it?... and that was up till now... Apparently, according to Robsia, he's called her now, and told her that it's never going to happen. Dare say after the pasting he go on here, he unleashed some fury on her after all... OK, so he may have come good only when his attention was brought to the fact that it was seriously bothering OP, but if all is to be believed, the wrong has been righted....
Maybe I'm odd, though I am not AT ALL known for my pathological need to forgive... I've got a badge in Grudge Holding... however, IMHO, once someone has seen the error of their ways and sought to rectify the situation, what is the point of still baying for his blood? Seems utterly pointless to carry on spitting venom at him, and highly likely to do more damage to a relationship than has been done already.
I can see that his life and decisions to get married are absolutely none of this woman's business.... Of course he does NOT need to explain himself to anyone least of all her....until, that is, when she becomes a problem. Which of course, he now knows she IS.
I think he's been a bit of an ostrich and not seen that there is an issue. Men often DO miss the subtleties and nuances. Only when we point it out to them that so and so was flirting, such and such gave so and so a funny look, often they miss it all.
I'm not making excuses for him, but I can so easily see, knowing what some men are like, that it's possible that he thought it would just die down on it's own and who the F is she for him to explain his life to her.
BigMac... So can I ask what it was you actually said to this woman, Robsia said you called her and told her, can you update me on that please?
Oh and BTW, seeing as I'm practically a lone voice in seeing your POV, BigMac, my advice is that the velvet gloves come off with this woman now. In addition to telling her on the phone, put it in writing, Text her to say that she is NOT welcome to call you, that you want no further contact from her. No calls are answered. Not one.
Start the next steps with Robsia as you mean to go on... You have not done that badly by her, but you certainly could have done better.
But right now, you have to clear out the clutter, get rid of this woman by any means necessary (legal!!) or I'll be one tiny weeny cog in a HUGE machine of MNers that will be actively telling her NOT to even consider marrying you until you have done this... ....OK?
Again, good luck.