Replace order number 12025902 d.d. 27-07-2015

I have orded 4 Zippy Compact 850MAh (3C) 25C Lipo Pack. They are not the batteries i needed. I orderd the wrong one. I need the Zippy Compact 850MAh (2C) 25C Pack.
How can I change the Batteries.

Pleas gif mee the answer how to sent these back and order the wricht one.