Billed but not activated

I took 2 sim cards from Mondo and struggled to activate them. I received an sms that its activated but weren't. I contacted their call centre but no one picks up. I emailed them and up until today never received an response. I then went on their FB page requested them to cancel as i was too angry after struggling to get hold of them and they rep****. Today i receive a bill for 2 sim cards that i never used or couldn't activate. I then called Telkom and they had technical issues and i was unable to get to an agent. I emailed Telkom and even tried the online chat but no one replies. After numerous calls to the call centre i finally get to an agent that then tells me that i had to cancel on the cooling off period which i told her many times how i tried to get hold of them. I am unable to cancel now and needs to pay. She emailed a statement which i also never received. There is so many number under my name but because of the bad experience it is hopeless sorting anything out with them.