No Refund

I ordered hens and they said I must pay R5299.00 .I paid on the 26/08/2017.On the 28/08/2017 they said I must pay extra R3250.00 for insurance.I refused.I cancelled the order.They said they will refund in 21 days.Now they say I must phone the bank for refund.They blocked my number on Whatsapp.they don't reply to my emails.What must I do?