No, I read what you wrote. You had an automated email, you responded by deleting your account. You got another automated email, from the same email address, saying your account had been successfully deleted.
You then engaged with a support representative, who deleted your data and email from their account system. What that representative did not do, clearly, is delete you from the (likely third party held) email system.
Note that the automated emails come from an elsevier domain, and the support email came from a mendeley domain. That is a good sign that you are in multiple systems.
Then, later, you again got automated emails from them. This didn't come from the support person, it came from the automated system the company set up, again likely with a third party and managed by a different team. Unsubscribe from those and they will go away.
Enter a valid email address that has never been registered with Mendeley. You will get the following message:
Oops, this email address was not found in our system.
But, if I enter the email I registered I get this message:
Thank you. If we have been able to identify your account, an email containing instructions on how to reset your password will be sent to you.
I don't receive an email, but Mendeley password reset can discriminate my previously registered email from random valid email addresses. That would be impossible if that registered email was only known to third parties.
Why would that be?
Look what I wrote at point 1.
1. 2017-06-07: Mendeley <mendeley@mail.elsevier.com> me "We have deleted your Mendeley profile and data, to delete your full Elsevier account, please email usinfo@elsevier.com"
So my Mendeley profile and data has gone, and Mendeley have deleted my data from Mendeley servers but it looks to me as though there is a central Elsevier server that still knows my email address.
Furthermore, Elsevier Product Insights for Customers password reset
https://e-pic.elsevier.com/forgot
rejects random valid email addresses but recognizes my previously registered email address:
Thank you. An email containing instructions on how to reset your password will be sent to you shortly.
And the password reset email actually does get sent to me!
Dear null,
You requested to change your password. Click the link below to change your password:
..
Well, what do you know! As far as Elsevier is concerned I do have an account after all!
You then engaged with a support representative, who deleted your data and email from their account system. What that representative did not do, clearly, is delete you from the (likely third party held) email system.
Note that the automated emails come from an elsevier domain, and the support email came from a mendeley domain. That is a good sign that you are in multiple systems.
Then, later, you again got automated emails from them. This didn't come from the support person, it came from the automated system the company set up, again likely with a third party and managed by a different team. Unsubscribe from those and they will go away.