no complaince /not send cancellation letter

my name is melumzi stali i have problem with debt wroks who i join debt review/counsel with later i cancel the agreement early last year since then they not yet send me a cancellation i've been calling send them emails but till now i'ven't got the letter. i've been bloked to use my credit card due to this debt works of which i cancel long time ago, i'm paying my credit card but can't use it please help me on this regard melumzi stali ID no: ********** 014085 debtworks ********** 627