********* business conduct

I signed up for a three months contract with Greencom, and I told them to stop my services yet they continued invoicing me and now I received a final letter of demand. I asked them to email me the contract they are demanding money for and they don't have it as the contract has expired. What I found ********* is that when I asked them to stop my services they agreed and didn't advice me that I will still have to pay for services i didn't consume. some months were reversed and some not. yet the invoices kept coming . they never stopped even when I ordered them to stop. Such ********* business conduct. do not sign up with this fibre service provider. it is terrible