Something fissshy about RCS Group's response to my request for credit limit reduction

I have called the RCS card division on 10 January 2020 to request them to reduce my credit limit. I was then requested by the call centre agent to write an email, which I subsequently did including several follow-up emails. The call centre agent gave me the email adress to send the request to but even up to today I have not received any acknowledgent of receipt of my email and I continue to receive statements with the same credit amout that I requested to be reduced.