As @jpatokal mentioned in the comments, the visa center worker seems to be mistaken. The visas that have been affected in this change are Z work visas, M business visas, and F exchange visit visas. The normal letter from your friend will be enough, I suggest you make another appointment and if you run into the same problem ask to speak to management.
Balglobal states:
Visas/permits affected: F, M and Z visas.
Credit:stackoverflow.com‘
5 Mar, 2024
4 Mar, 2024
4 Mar, 2024