Refusal to cancel order and refund

I used to be an Afrihost client and had no issues, and thus referred my parents to them. For them the service has never been great. In March their router died, and after calling Afrihost with assisting with testing the line etc (before realising it was the router), they decided to order a router from Afrihost as they provide a warranty. He was immediately invoiced (14 March) and the funds were debited from his account on 17 March. He called later that week to query the delivery of the router of which he was told the courier company has not collected it yet. When he eventually received the router (25 March), it was discovered that the router is faulty, as per a technician, which my dad got to call Afrihost to confirm the issue. Afrihost then sent for the router to be collected on 1 April. My dad since decided to cancel the order of the router (An email was sent on 1 April requesting the cancellation) as he could source one himself in a much shorter time, as he has been without internet for more than 3 weeks (His total cost a month is R 156 and was credited for no internet an amount of R 46.96 - not sure how they got to this amount). He was also double billed for the courier of the router - which they credited upon request. When a certain technician assisted him to install the router, he sourced himself, he was told to hurry up and that he is taking too much time. This is totally unacceptable. My dad is 66 years of age and not tech savvy. When you call in, they ask for your ID number to verify your account, so the technician could realise his age and have a little patience, but still he was treated with disrespect. When he phones for help, they offer to call him back, but never do. Afrihost has ignored his request to cancel the order of the router, as they claim they cannot refund him, because the router now belongs to him and according to their warehouse the router is not faulty - even though a technician they sent out confirmed otherwise with them telephonically. I then called on my father's behalf to query the issue. I then reminded the lady that a customer has 10 days upon receipt of a product, to cancel a purchase should it not be satisfactory. She took my number to call me back, but never did. Since then, they sent their couriers again on 5 April to deliver the faulty router, for which my dad refused delivery.