Contract cancellation

I personally will never recommend any of my close family or friends to cellc however at their own risk meaning cancellation contract with cellc is hell of stress, hassle and difficult to deal with cellc agents,I have sent 30 days cancellation email notice as requested and server as proof whether or with no response , i have already dealt with 3 cellc agents promised to resolve the issue since till today disappeared, unacceptable service and now I have calls from VVM Debt collectors thinking I will be scared, I asked them one question only they dissappeared, Button line is as long as I have proof of cancellation notice. I thank cellc for pathetic service received .