Key fob/alarm issues

  mercedes/c-class/2008-2015

I have a 2008 Mercedes C 300. The key Fob will only work if you are very close to the car and it will no longer make chirping noise when the car is locked. I took it to a Mercedes dealer they told me the alarm module that is located behind the front tire on the passenger side was bad. I went to a local mechanic and replaced the module but still have the same problem

11