"请帮我换货或者退货"英语怎么说

could you please return/exchange this for me?

请帮我换货或者退货"英语怎么说
换货---exchange sth
I need to exchange this dress. It is too small.
退货---return sth
I would like to return this dress.

exchange the goods or withdraw the goods
change 指改变
换 [简明汉英词典]
barter
exchange
trade

Please help me change or return the goods.