bad customer service and over charging

Aramex has picked up this parcel on the 18th of October 2017, Ref J189A94, and I was under the impression that the parcel was well underway to the destination. However when I first followed up more than a week later the parcel had not yet left and you informed me that there was documents required due to the lithium batteries in the trackers. I sent you the information ( MSDS sheet and battery declaration and the original tax invoice ) on the same day and now 14 days after you picked up the parcel you want to charge me R 9 916-37 for the freight at least this has come down from the initial R 12 296-88 that you wanted to charge me last week. What concerns me the most is that I am returning the parcel to the company whom I bought it from, and the freight charges from China to South Africa was US$ 73-00 with Aramex. How is it possible that exactly the same packeage with the same content in the same box can be R 8 000-00 more expensive going to China than coming to South Africa?