signal and Internet is so poor !

My signal on my phone has been so poor these last few weeks , and not to mention my Internet is extremely slow that you often just close it as it's taken so long . Calls are either missed or if the call goes through the other person can't hear me or I can't hear them , when you on the phone the line just drops try calling back and all I hear is line noise . it's happened in a number of locations it started off at my house and now has got progressively worse . If this doesn't improve I will have to cancel my contracts with you as what good is it having a phone I can't make or receive descent calls on and I can't use the Internet as it is so painfully slow. As a female it is extremely dangerous not being able to call someone or poeple hear me when I do