Bad Service from Discovery

Due to financial difficulty I had to cancel my Medical Plan in Sept. This morning I received an email from Discovery telling me that I owed them money. due to leaving before the end of the year, understandable. Minutes later I received an SMS \You have not responded to requests for payment. Please call Discovery Health urgently to avoid being blacklisted"Ten minutes later I received the same email while I was speaking to the call centre. The agent told me that they had sent me an SMS on the 20th October 2015"