Billed for magazines/fin product without consent

I received two sms's now stating that i am owing on my Markham account, knowing very well that my account is paid up and even had overpaid. There is a number to call on these sms's of which i did call in order to rectify this. The lady named Portia answered the phone, took my ID number to view my account. She then told me that she can see that i have an outstanding balance and it may be due to magazines or financial product i have with Markham. I explained to her that they did call me in the past and i have declined any product they offered and she advised me to contact customer service. Why should i be contacting another department when she can contact them with my query or even send them an e-mail to contact me to sort this out? Why should i be spending money on phone calls when they are the one billing me incorrectly. They are able to pass on the referrals for their marketing yet they cannot do the same to sort out their billing with a customer who has been loyal to them, never missed a payment since 2004? Am i less important compared to when they call me to sell products?

This is worst customer service of any kind where the retailer is spitting on customer face.

I would love to know since when they started adding these charges on my account, how much in total have i paid for this ridiculous products?