How to cancel

[Chuck19]

I would like to cancel all my Avast subscriptions. How do I accomplish this?
I am tired of being bombarded regularly with offers for new services which I don't understand. I'm in a situation now where I don't know what I've got or what it does and why I still need more products. This is too confusing:  I just wanted an antivirus and the minimum of any other services. I don't want to spend my time trying to figure out what all these extra services do. 
I just want one package with all the things that I need included and I will be shopping around for one of those.

[DavidR]

Cancelling automatic renewal of the Avast subscription - See https://support.avast.com/en-en/article/35.
I use Avast Antivirus Free and have been for close to 20 years, that suits my needs. 

It is hard to give detailed answer, given there is little detail to work with:
What is the main Avast program that you are using, Avast One Essentials, Avast One Silver, etc.

The Avast One Essentials (free product) for Windows, would probably be sufficient and it gives a little extra over my version, but is less configurable.
Hereby lies my problem I have never used the Avast One product, so I can't speak from personal experience.

[Chuck19]

Thanks for your reply.
Apparently my message wasn't clear: I want to cancel all my Avast subscriptions and get a prorated refund for the unexpired terms.
I hope that clarifies my intentions.

[DavidR]

First I don't work for Avast, but am an Avast User.

You would have to ask for a refund, I'm not sure about a pro-rata refund for the remainder of the term. 
Refund request - https://support.avast.com/en-ww/contact/sales_refund If you haven't got the Order ID, etc enter 00000000 and give as much information that you can to help identify it.

As far as I'm aware you can ask for a refund within the first 30 days and you should get a full refund, outside of that I'm not aware of any pro-rata refund.