Spark Energy Bad company houston Texas

My parents got aproch by someone from this Spark company. My parents don't speak english so they give my name and number. They told them it was for electricity not for gas. When I got the call they were so fast on the line that I ask them to go slow and explain and they say they were going to sent everything on the mail. I never received anything. They trick a lot of our neighbors too. My parents dont spend 30 dlls in gas. they only use about 10 to 15 dlls. why is this company tricking people to get their services is not fare. 

please help...