Home phone charges???( bellsouth)?

My phone bill had alot of extra charges from 3 different companys that billed me me and it charged it to my phone the lady that i spoke to from bellsouth said that its kinda of like spammers how can they do this and this was the first time i had noticed this and bellsouth is only taking off charges for 3 months back it was like 150.00 this month it was from companys i have never even heard of how can this be legal???? has anyone ever had this happen to them?