Fed up with Mrpmobile

I took a contract with mrpmobile and once the expiration date of the contract was due I was called for renewal / upgrade which I declined due to numerous issues I had with the carrier.... Now a year later my account is still being debited and I'm constantly getting calls to inform me that I'm in arrears... Now how am I in arrears if I didn't renew or upgrade and secondly how am I responsible for a cancelation fee if I didn't cancel but I just didn't renew or upgrade... I'm sick and tired of reversing monies as this is affecting my credit score and I'm also sick of the constant calls.... If I'm debited one more time I will take this up