Billed for no service

My phone line was out of order for over a month, this was reported to Telkom at the end of July but they only managed to fix it by the end of August. On the 26 of August I received a mail from Noleen (Telkom social media SM135519) informing me a credit will be passed from the date I logged the complaint about the line being faulty till the date of it being fixed. I received a bill from Telkom for the full amount thus no credit was passed and I still got billed for a non-existing service. It took Tekom over a month to repair the faulty line.... Where is the credit?