******** debiting

on April 7th 2015 I received sms's from this company, I ignored it because I wasn't interested in their product. then sms's came with policy numbers, which didn't make sense, again I ignored it. yesterday, April 30th 2015, money was deducted from my bank account. nobody phoned me for my banking details, which begs the answer to the question: where did they get my banking details?! no permission was given to anyone! i have never been or will ever be a client of this company. any advice?