Flew LAX-HKG yesterday in F

FA comes around offering pajamas and I ask her for size recommendation. She suggests M and I accept before she gets called away to handle something. In between, another FA arrives to confirm my beverage and meal order. First FA comes back with a pair of S and L in her hands. I ask about the M and she tells me she gave to another pax and they're now out and only have S and L. When I remind her that I requested the M she apologizes and says they only had one pair (cabin booked 4 out of 6).

Senior purser comes around a few minutes later and introduces herself. When I explain the situation, she appears shocked and promises to investigate. A few minutes later she tells me they didn't provision the flight with M, only S and L. When I told her the other FA said she gave away the M, she insists the M weren't provisioned at all. Hmmmm. Not sure who to believe though it doesn't really matter since I'm not getting M either way. The purser states she will "send a message" to her operations team and took my email address. I received no follow-up.

Is this a normal situation on CX? Very disappointing!