Refund

I have recently purchased hair from zqhumanhair store on AliExpress and since the shipping was free I was told that my hair will be delivered in my nearest post office, then a few days back I got a message from the post office telling me that my parcel is ready for collection and I should come with R235.76 in cash so I can get my parcel, I got there and I was told that they made a mistake I should actually pay 725 Rand's. I told my seller about the issue and never got back at me now I would like to request for a refund because there is no possible way that I can pay 700 for just collection of the hair. Please kindly assist the post office is Amazimtoti post office.