Frustrating Cancellation of NTT docomo Hikari Contract

Hi I have spent last 4 days going in circles to decide whether
Moving my current subscription
Or Cancellation and joining new subscription is optional.

Context:
I have NTT DOCOMO Hikari for Internet Wifi with T-Com and Ahamo for sim plan
The contract expires in December and I can cancel Jan to March for free.

I am moving November end.

I wanted to first move the same Internet there to new place. Use it for month and cancel.
I applied for the move process.

It costs ¥2200 for application online plus the operator today told me that Kōji is must and cost can be ¥12k.

Which I thought is optional and hence I chose to cancel contract with Hikari and keep ahamo.

On the call for Cancellation they told me a load of things which made no sense to me and I was lost.

Things like.
You might have to pay penalty if equipment is damaged
You have to cancel all services of NTT
Your options added with NTT is canceled from now
Your online call supports from NTT is also cancelled
You have to return equipment via post sent to your house.
You have to yourself call Internet Service Provider and call them to cancel your contract pay cancellation fee or keep it and pay fee for keep using
You have to answer call of NTT and confirm cancellation details
You will be charged until the line installed is removed
You will be charged for full month the contract ends.

I am lost at what does the contract with ISP mean? I never knew we have to cancel and pay separately for NTT DOCOMO and ISP(t-com)
What does the [You will be charged until the line installed is removed] mean? I did not install any lines. It is an apartment and they have the line or optic fiber on wall I didn't install anything.

What is the step to be taken?
I don't understand anything she said and it was overwhelming me so I just said yes just take this back I dont want to do anything with Docmo. And I asked her does my ahamo get affected she said nothing on it.

Also I asked her a lot since I was informed the Kōji is optional and can be done after move… why she kept saying it is must. Never said its optional.

About charges for cancellation, what all are the charges or things I need to care about here after. As I have already moved to cancellation.

Please 🙏

by dahiya_original