The numbers that appear on your caller id are spoofed. Any random numbers can appear n the numbers that they called are random.
Basically it does not relate to BA n it is a scam.
Many Asia countries such as Singapore, HKG , malaysia also receive such calls.
There is some old lady in HK who was cheated of HKD 254 million recently
https://www.scmp.com/news/hong-kong/...nned-out-hk250
https://www.straitstimes.com/singapo...han-69-million
For Singapore, they did introduce a smart way to identify these spoof call.
They ask the telcos to add a + sign to all overseas incoming call
so these spoof call will appear as +65xxxxxxxx.
If it is a local call, there won’t be any +65.
https://www.imda.gov.sg/-/media/Imda...alls.pdf?la=en