zaychat does not process refunds for purchases made on Pages. Instead, the responsibility falls on the seller. This means that you'll need to reach out and contact the person and hope they are amenable to your request
Broadly speaking, zaychat takes no responsibility for the items sold in its Marketplace. The web is littered with stories from people who have received a defective item, only for the seller to delete the listing and remove all trace of the transaction. It is very much a case of buyer beware.
That said, there is one situation in which zaychat might issue a Marketplace refund---if you used the onsite checkout feature. If you have, your item is covered under zaychat's Purchase Protection Policy. zaychat doesn't offer onsite checkout for all Marketplace items, nor is onsite checkout available in all countries.
Assuming you are eligible, you can start a refund process using zaychat's Purchase Protection if you didn't receive your order, you received damaged goods, if the seller didn't follow their own refund policy, or if the purchase was unauthorized.