Feeling ****med by mr price

I was called by one of Mr price agents about a sim card i would receive dor being a loyal customer and it would be a once of thing. I couldn't understand why my account balance was so high but i paid it but this month again i went to look at my statement i saw I was paying for the sim card and no one told me it was a 12 month contract I was agreeing to. I feel like I was misled and is deeply disappointed