I'm so disappointed

Hello Peter please help me I bought a phone at Ackermans cellphone store at Fourways mall using pay joy,I paid a phone 3 months installment and when I'm done with the payment pay joy block my phone then I took it back to where I bought it and they say I can come the following day to collect it,when I come the following day they told me that pay joy didn't respond.Then the other day they told me that they sent an email they I still waiting for pay joy to respond.Even today is been 2 weeks now.Can you please help me to get my money back because now I'm suffering I used my last money to pay for that phone so that I can be in touch with my kids.And when I tell the guy at ackermans that I want refund because I don't owe that phone and I need a phone asap he told me that I have to contact pay joy because there is nothing he can do.please help me to get my refund I don't want anything to do with ackermans or their phones anymore.