How to cancel subscription if data are lost?

Dear Avast-Team,

I’m IT-Specialist, and I’m responsible for the IT of an older lady. Some time ago she has enabled (however) the subscription for Avast, and now every year she has to pay €29,99 for renewal. Now we have to disable this.
But she doesn’t have any credentials (anymore?). All we have is a name, birthday, adress, customer no and email-address.
I tried the option “forgot password”, but your system said “This email is unknown”.
What can we do?? On her finance papers there’s following text …

“DRI*AVAST Softw. Shannon Co. 29,99€”

Personal data I can provide via PN

Does this help??

Regards,

Kangaroo72

Submit a ticker > https://support.avast.com

http://support.avast.com/support/tickets/new