I have found how to prevent members deleting their own post, not a problem, now after inspecting the admin panel I note that a few members have deleted their own account. 
Can I prevent this? 
Thanks.

Hi @logo1960,

Even if you disabled the option to delete accounts in the Administration Panel, it is still possible to unsubscribe from a Forumotion forum via https://www.forumotion.com/unscribe

Please see this topic regarding deletion of accounts.

No, I do not want to delete myself or the forum, I want to stop members deleting their own accounts from my forum.  
I had a few members join make a post (spammy) then delete their account. 

When I search their email account through the Admin panel the user is not found. 

I can stop members deleting their post but want to stop them deleting their membership.

Yes, I just said that you cannot prevent members from deleting their accounts, even if you disable the option in the AP. You have already disabled that option, correct ?

I haven't disable it because I can't find it.  Where is it please

Go to Administration Panel > Users and Groups > Users > User options

Find "Allow members to unsubscribe" and choose "No"

Ok thank you, I had already done this, not the wording I was expecting. obviously does not work. but hey ho, members are sent to try me 

Solved

Even if you activate that, a member can still unsubscribe by using the link posted by Ange Tuteur.

It is a problem with Spammers,  they can register their email make a spam post and then leave, not ideal, just means more work.  
Many of the members ask or make a polite request when they want their accounts deleted, that is not a problem, and many members we have to hold their hand even when posting! 
Maybe it is a Forumotion problem to look at.  Spammers are a pest at the best of time, and when they find a loophole then become a menace. 

Thank you for your help and advice anyway.

Hello,

If you or a staff member are online when the spammers post you can ban them... Or id an admin is on you can deactivate the account, this will not allow them to login to delete the account via the link in the profile. This allow you time write down the email address.

While yes they can still delete it voa Ange's link.. It will give you more time and chances are a spammer won't know about that link.

-Brandon