Reporting back...

My wifi charge made on 12/18/2022 was finally reimbursed on 5/26/2023, after support tickets opened with Barclay and multiple follow-ups. Apparently the "glitch" is only with Panasonic wifi, which is used on widebody jets. Just really frustrated by the lack of customer service during this process. Almost no agent even knew about this benefit. Compared to other banks, where agents would usually make manual adjustments for such small credits, Barclay sure makes it difficult by going through a lengthy investigation process. To me, that's just a huge waste on human resources. To this day, I still don't know if it was indeed a systematic issue or an individual breakdown. Oh well.