No compensation for phones that has been promoted with wrong amount

Dear Sir/Madam I've am with Vodacom for the past +-10 years and this is absolutely a no go for me what I've experienced the last 3 months. I did a online purchase of a combo deal of two phones with an agent who phoned me. She told me about this promo of an amount for the two phones which I repeatedly asked her if it was the right amount. Long story short I've received the phones. When I received my bill what a shock . Agent gave wrong information . After the second deduction I informed Vodacom . They told me they will investigate the come back after almost a month which they confirmed that they were in the wrong . There final solutation was that we send the phones back because that was the only way they could come to an agreement with us . Because of that we don't have phones now and we couldn't come to an agreement because of them that could not compensate us wich I think is very unreasonable., and I think that the service is very poor ., they've admitted that they were in the wrong but could not come too an agreement with me.