When did you send the mail? I sent a mail too via Web form about my visa will expire soon but no reply yet...Nothing new. It is getting heavy.
I sent via email a letter of intent from my employer regarding changes in my employment and did via the webform as well, just to be safe. Obviously, received nothing back and don't know if they'll ever get the document.
I'm gonna try to call MP this week. I'm not sure it won't be so helpful though.