I'm sorry to hear of your experience, it is always too bad when customers are displeased with service levels.

However, my opinion is that the F cabin - this is my opinion only here, and I'm just a single businessman who happens to be a CX frequently flier, so take this with a grain of salt - is indeed quite a premium product, and I believe customers should have to pay significantly more to obtain the luxury of sitting there. Ex-TPE J tickets are already pretty cheap to SFO (somewhere in the $90-$100k NT range if you're buying D class, or about $3k+ USD). In my opinion, $60k NT is hardly anything to pay for the infant round-trip in F. Indeed, customers paying for J or F probably should be able to afford that, and definitely I know when I'm seated in F I absolutely do not want other pax bringing their infants into the F cabin for minimal or no charge. As a paying pax I would expect there to be a significant hurdle for infants, to reduce the # of aspirational F pax taking their kids to the front of the plane. Definitely a bit of caveat emptor here (when buying with miles), F is not meant to be cheap and ancillaries (such as infant fares, unfortunately) will not come cheaply.

For me, it's not so much about what the infant "gets" or doesn't get in F class - it's the fact that they're there, and despite how great all the parents think their kids are there is definitely the statistical probability that the kid is going to cause some sort of a nuisance, potentially alienating a high-rev pax who is paying full fare F. I can say, as someone who does enjoy flying F, that (for me) F has little to do with what I "get"....it's more about what I don't get (or get less of). Less noise, less lights on and off, less bustle, less talk, less movement in the cabin, etc. etc. It's just overwhelmingly more peaceful than J class. Adding kids, I think on average it can be agreed, generally adds to all of these things. I know some young children are amazingly quiet and well-behaved (and definitely some adults are just the opposite), but I would say on average the probability for disturbances are likely higher for a really young one, unfortunately.

I do, however sympathize with the customer service angle. It does seem like you should be able to get a miles refund but you'll probably have to play it cool. Although they can seem unwavering and ridiculous sometimes, I've had a number of instances where MPC and reservations have really gone the extra mile for me against their policies in the name of common sense, after I got through to someone (usually a supervisor) who is empowered to make real decisions. To me, this was very appreciated as a customer. Each time I was patient, polite, but firm with my points (which I thought had a bundle of common sense, I wasn't trying to "scam" the system in any way). One was for a full Y refund without any change fees, because I went full-fare J on the route instead (I originally bought Y and and was planning to upgrade with miles, but ultimately went in paid J instead). It seemed odd to me to have to pay a "refund" fee even when I was going on the same flight and paying almost 65k more HKD for the privilege! It was slightly insulting to add a HK1200 refund fee on the original Y ticket since I was going to fly on the plane anyway, and the supervisor was kind enough to agree with me. Another time (x2) I had to change my CX flight date due to other airline delays. Once I missed a flight due to a 30+ hour JAL delay I had last year, another was a 12+ hour AA delay this year. There was a change fee for each CX flight, but were waived by CX despite having bought the JAL and AA itineraries separately. They were totally unconnected to my CX itinerary (one was NRT-HKG, the other was SFO-HKG).

Each of these three instances, CX's initial response was "no." But I was patient in explaining my logic, and had no problem after spending a little time on the matter.