% APNIC found the following authoritative answer from: whois.apnic.net

% [whois.apnic.net]
% Whois data copyright terms    http://www.apnic.net/db/dbcopyright.html

% Information related to '2402:800::/32'

% Abuse contact for '2402:800::/32' is 'hm-changed@vnnic.vn'

inet6num:       2402:800::/32
netname:        VIETTEL-VN
descr:          Viettel Group
descr:          No 1, Tran Huu Duc street, My Dinh 2 ward, Nam Tu Liem district, Ha Noi City
country:        VN
admin-c:        TVT8-AP
tech-c:         NDT9-AP
remarks:        For spamming matters, mail to soc@viettel.com.vn
status:         ALLOCATED PORTABLE
mnt-by:         MAINT-VN-VNNIC
mnt-irt:        IRT-VNNIC-AP
last-modified:  2017-11-12T03:16:55Z
source:         APNIC

irt:            IRT-VNNIC-AP
address:        Ha Noi, VietNam
phone:          +84-24-35564944
fax-no:         +84-24-37821462
e-mail:         hm-changed@vnnic.vn
abuse-mailbox:  hm-changed@vnnic.vn
admin-c:        NTTT1-AP
tech-c:         NTTT1-AP
auth:           # Filtered
mnt-by:         MAINT-VN-VNNIC
last-modified:  2017-11-08T09:40:06Z
source:         APNIC

person:         Nguyen Dang Tiep
address:        Viettel Network Corporation
address:        No 1, Tran Huu Duc street, My Dinh 2 ward, Nam Tu Liem district, Ha Noi City
country:        VN
phone:          +84-24-62989898
e-mail:         soc@viettel.com.vn
nic-hdl:        NDT9-AP
mnt-by:         MAINT-VN-VIETEL
last-modified:  2017-11-11T09:40:35Z
source:         APNIC

person:         Tran Van Thanh
address:        Viettel Network Corporation
address:        No 1, Tran Huu Duc street, My Dinh 2 ward, Nam Tu Liem district, Ha Noi City
country:        VN
phone:          +84-24-62989898
e-mail:         soc@viettel.com.vn
nic-hdl:        TVT8-AP
mnt-by:         MAINT-VN-VIETEL
last-modified:  2018-08-21T09:57:13Z
source:         APNIC

% Information related to '2402:800::/32AS7552'

route6:         2402:800::/32
descr:          VIETTEL-VN
origin:         AS7552
mnt-by:         MAINT-VN-VNNIC
last-modified:  2023-05-26T19:38:25Z
source:         APNIC

% This query was served by the APNIC Whois Service version 1.88.25 (WHOIS-AU1)

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