Why can i receive calls and messages but send them

[AC Question]

I receive calls and messages on my Samsung phone but I cannot send them
when I attempt to call someone I get put through to the spark helpline and when I try to text it turns gray and says Failed SMS
please help how do I fix this
or Is this a problem I should talk to spark about?

 

[B. Diddy]

Welcome to Android Central! Are you on Sprint? Have you spoken with them, or whoever your carrier is?