Billed ********ly and incorrectly again!!!!!!!!

After all the drama to finally have the prior incorrect billings credited Vodacom have gone and done it again. They have billed me again for my old handset installment of approximately R307 in October 2017 (Invoice Number H3-5EC2F). After contacting the call centre on 21.10.2017, and subsequent follow up calls on 2310.2017 and 25.10.2017 no response to date. Stop billing me ********ly and credit my invoice for October 2017!!!!! To what degree must we as customers accept such poor service!!!!!!!!!!!