4 months waiting for assessment on faulty goods with no communication.

So I bought my 8 year old son a I-Play amphibious racer on 17 December 2018 for his coming birthday 3 January 2019. He was very pleased with his gift, but soon we realised it stops working after it does a few flips. Tried new batteries, and still not working. 4 January 2019 both of us went to Makro Centurion to return the unit. But it was communicated that due to the purchase date, this unit is only to be sent in to the supplier for assessment. So we did. Now after a lot of enquiries and people not returning your enquiries, the unit is still at the supplier. Makro still refuses to give a refund. I think we are far beyond a reasonable time for assessment. And so my son still sits without his birthday present.