Extremely BAD SERVICE! NO FEEDBACK!

I have had the unfortunate pleasure of dealing with Web Africa's bad service. I recently returned 2 routers to them for 2 LTE packages I canceled and to my surprise I got billed for the routers even though I received proof from the courier that they did, in fact, receive the routers. I contacted them, took me almost 40 minutes to get hold of someone to assist me. The lady promised they will resolve the issue and credit the invoice. After 2 weeks I got a notification that al my other LTE services has been canceled due to nonpayment even though my account was up to date but according to them, this was regarding the 2 routers I have "still" not returned. I again had to spend more than 30 munites to get hold of support and spoke to Amanda, after a long fight she confirmed they did indeed receive the routers and that she would credit my account and reactivate my services, finally my problems was solved... or so I thought, when I got home I saw Amanda credited the wrong invoice and only 2 of my services were reactivated and the rest not. So what the hell do I need to do to get this issue resolved? Webafrica is definitely not a viable option anymore.