utter poor service - no credits done for 6mnths

After numerous emails, calls, follow ups, complaints lock and complaints on Hello Peter regarding the service I receive from Vodacom. since 31 July 2015 when I cancelled my wi fi contract within 2 days not even 7 the device was only collected the 15 Dec. 2015. again the 13 Jan. 2016 I followed up what is happening with my credits on my account ' cause again I see that I get billed for the wi fi device. on the 14 Jan 2016 in the afternoon I received a call due to the issue I locked (REF: S3-GKL72-ZXHM) according to the lady I spoke to still was the Wi-Fi active and not deactivated as Busi promised me on 31 July 2015 after numerous calls to lock the issue Vodacom staff assure me the they will deactivate the wifi immediately.. for 6 months I am paying for something I did not used at all and they are more than welcome to check the sim if any data was used or locked in after the 31 July 2015.. no one is phoning me back! I want Vodacom to send me the CEO's detail may be he / she could sort out this issue be January debit order is been deducted. I am gatvol for this if I don't constantly reporting or following up nothing happens!