Deducting money

<p>I gave a month notice before my contract ended to cancel the contract. Acc no ********** 38. I received confirmation that the contract was cancelled successfuly. </p> <p> </p> <p>I received an email dated 1 April 2017 for inv no ********** 414 for an amount of R49.00. This amount went off my bank account end of April.</p> <p> </p> <p>Now I receive another invoice for R22.87 inv no ********** 413 dated 1 May 2017. What is this amount for. Why am I still being billed of this contract was cancelled</p> <p>I want answers asap or will be taking further action</p>