Android Question

hey i have a metro pcs coolpad my voicemail is already set up i had this phone for 2 years already and this has never happened but it appears to me that when i called my voicemail today it asked me for my pin i enter it and it says please enter your password ,i do it again and it says sorry your having trouble please try again later ive tried restarting my phone taking out the battery everything im wondering if this has happened to anybody before and is there any way to fix it