Allow her to have a few days to reply your PM, sms-es and calls. At the same time, PM her about this thread to ask her to solve with you.

Registered post varies from the weight and the size of your parcel. The price for the registered post slip is only RM1.70, but sometimes, your parcel will be charged RM2.50, RM3.50 or even more.

Pos express varies from RM2.50 depends on the size of the envelope. However, you might risk of loss of parcel as pos express is only put into your post box, without anyone to receive your parcel.

According to your post, you mentioned that the tracking number post code is at Batu Caves, perhaps she wrote the wrong address. Or, she had mistakenly gave you the tracking number.

By the way, thread moved.