Hi,
We already dealt with cases like this one in past. As far as I remember, the approach is following:
Whenever a player requires the self-exclusion, the best option is to do it in their own account if the casino offers this option. If it's not possible, then it's better to you contact methods that are faster than email - typically live chat or a phone.
When the player contacts the casino via email, then we believe that the casino should close the account within a "reasonable" period of time. I'm not sure about the current internal rules we have for these cases, but it's between 24 and 48 hours as far as I remember. If the casino fails to do so, then it's casino's responsibility when the player loses the money.
Your case is specific in a sense that you've been provided a wrong email address. Thus we already know that they'd never close your account even if you waited longer. Anyway, if you contacted them only via email and then lost the money "few hours later", then I believe it would be your fault. Simply because you can't expect that the casino is going to deal with your email immediately. In some casinos, they really get a lot of contacts every day and then they deal with it one by one chronologically. Then giving the casino 24 hours at least to deal with your email sounds reasonable.