MFC harass their client in good standing

this company treats its clients like they are 5 year old's. I have never missed a payment and manage my accounts impeccably but every single month i receive sms's one after the other to remind me that there is an upcoming payment and then i also receive at least 3 "courtesy" calls to thank me for keeping my account up to date. i have mailed them to stop harassing me to which i received acknowledgement that they have flagged my number to stop receiving calls and sms's but yet they still continue to harass me every month. i am now becoming abusive when they call me which is not in my character. i am considering going the legal route to stop this harassment.