Umbilo Branch, with regards to customer service , I want to do a contract cancellation but I have not received the necessary written documentation to proof that the contract has been canceled

Umbilo Branch, with regards to customer service , I want to do a contract cancellation but I have not received the necessary written documentation to proof that the contract has been canceled. I have called many times, but no feedback was given until now. I even sent an email but no response. Very disappointed