Seller doesn't want to refund payment for defective phone

Hello and Good Day!

Would like to ask for an advise. We bought a 2nd hand iphone 6s+ in a stall which they mentioned 100% in good condition. Initially checking there were no issues, but upon using it within a day, the battery seems defective. So we went back to the seller and they mentioned they can only replace the unit. Now the problem is that they dont have any same unit available, but they wont refund it either. My wife who bought the phone is also stressed because of this and the fact is she's pregnant. We just want it refunded to resolve the issue. Can this be a violation of the Consumer Act? and maybe moral damage to my wife?

Appreciate your advise on this. Thanks!

since this is a 2nd hand device, i don't think this is covered under certain warranties unless specified specifically. does it specified that there is a refund policy?

Hello.
They just mentioned NO REFUND but its not written anywhere even in the receipt. They did say that they can replace the battery, but it doesn't look right since we just bought the phone and in less than 24 hours, it will be repaired already.

unfortunately, that is the risk you take when buying 2nd hand items.

Ok. So there's nothing we can do in this case?

just continue coordinating with the seller since it seems they are willing to fix the unit.