These are bargain goods, you can't refund or exchange.

这是特价商品，我们不退也不换。

youdao

Refund or exchange measures, address and relevant situation of direct selling commodity;

直销产品退换货办法、退换货地点及退换货情况；

youdao

Do not accept the clothing does not fit, different colour as a refund or exchange reasons.

不接受衣服不合身，颜色差别为退款或换款式的理由。

youdao

Rail company Eurostar said about 30, 000 passengers had been due to travel on 50 services on Friday, and would be offered a full refund or exchange.

BBC: Weekend hit by tunnel disruption

Returns without a receipt are subject to the posted return policy, which might result in your receiving only a merchandise credit for the lowest price the item has sold for recently, or possibly no refund or exchange at all.

FORBES: Returning A Gift? What You Need To Know About This Year's Return Policies

Upon calling them again I was told that this was standard procedure in the event of faulty goods and no refund or exchange could go ahead without this visit, despite a previous agent telling me that the pictorial evidence was sufficient to effect this action.

BBC: Fergus Muirhead