Airtime or money

I bought 300r airtime telkom, to a trainee staff when I get home I checked and find out that he sold Vodacom . Try to go back to explain to my surprise the manager don't even want him to take responsibility. He said is my fault. Mind I bought it late and I couldn't check in time because I trusted the cashier that he had that's the reason he did not confirm with me if I said telkom or Voda. I want my money or telkom 300 as I don't have vodacom and I don't want vodacom