Still we don't have received this order till date and unable to track the status our parcel showing error (Parcel#RV883815498CN is invalid, China Post has not received any parcel associated with this number! )I'm paying also express delivery charges. if you unable to delivered my parcel so plz refund my amount Kindly look into the issue and resolve it.

http://track-chinapost.com/result_china.php?order_no=RV883815498CN shows the number is invalid.

This means your seller never actually shipped anything yet. you might be scammed.

if you just got this number, You should push seller to ship the goods immediately. Tell him if you can not track real shipment data in next 3 days, you will open dispute to aliexpress/amazon/ebay/paypal against fraud.

If you have got this number for long time and paid with paypal/aliexpress, you should open dispute against fraud and claim refund.