Looks like we have another one who likes to receive spam mails.
Emma, it is a really bad practice to post your email on a public webboard.
Bad guys are harvesting them and abuse them.
Please read the thread before posting in it.
Answer has already been given in replies 43, 48 and others.
1]
It is not up to avast to stop the sms notifications.
You can disable them if you want.
2]
It is not avast that get the money from the sms's.
It is your service provider charging you for them.
3]
It is not a bug.
4]
See 1]
5]
It is/was your own choice to have the option enabled.
And since it is not a bug and not avast who charged you, you are not entitled to a refund.
If you get a refund, fall on your knees and kiss the ground.