Telkom ignoring request to cancel my landline service

I requested my landline service be cancelled on 2021-07-17 (reference ***4). Telkom promised a consultant would contact me in 2-7 days. That didn't happen. Telkom's selfservice portal shows my cancellation request as "resolved" (with no explanation on whether that means Telkom as actually cancelled my service or are ignoring my case). Telkom's call center (both voice and via chat) are unable to help. Emails to the various Telkom departments (e.g. Sales, Technical) respond with a pre-canned "please talk to Sales" message. It is impossible to find a Telkom employee that can help me.

How do I cancel my Telkom service?