Stalling to Refund

We bought a vehicle at Gauteng Vehicle Auctioneers in Randburg for R134 986.70 on 19 June 2017. The sale was cancelled due the vehicle having serious Safety Issues with no airbags and no mention of this before sale. SA Gauteng Vehicle Auctioneers confirmed cancellation with full refund, with signed written confirmation. He arranged to pay us on 1 August 2017. On the 1st, he came with stories, he will pay on the 2nd. on the 2nd, he only paid R30 000. He then agreed to pay the full balance on 9 August 17. On the 9th, he only paid R35 000.00. On the whatsup message, he ‘promised’ to pay the balance on Saturday 12 August 17. 16 August 2017 he is ignoring my calls, stalling me by saying the balance was paid on whatsup, but he does not have proof. ****r Mohammed owes me R70 000. He had my money since 19 June 2017. He took my money and the vehicle. He is stalling and stalling and consumers have to be aware of his actions. It cannot be legal to take a person's money, agree in writing to refund, and then stalling.