I have the same situation. does the seller has the right not to refund my deposit if I change my mind due to circumstances change?
Maybe yes, maybe no.
Scenario A - a registered breeder, operating a proper business
In simple terms, the vendor doesn't get to keep your deposit... for nothing.
But....
On the one hand, a deal, fairly made, is a deal.
That's the point of contracts in the first place.
And that's why mere change of mind by one party is
not typically a ground to release a person from a contract.*
On the same hand, one party doesn't always and automatically have to "bear the cost"
of another party failing to perform their side of a contract.**
So, for example, a seller, say for example a dog breeder, can be entitled to recoup the costs
of looking after a customer's part-paid-for- animal over the time between purchase and delivery.
On the other, in the circumstances of COVID, you may find that where, say, one party loses job income,
that to insist on performance of a contract of this kind could be unconscionable conduct
(note, there are many ifs and buts attached to this scenario, and none of it as of right...).
On the other other, you may be able to strike a deal with the seller to refund you
if they can quickly and easily find another buyer.
Scenario B - buying from an unregistered/ hobbyist/ "backyard" breeder
In the worst case scenario...
You have no consumer protections.
You may not have any reference material (such as a written contract) to refer to.
Your purported contract with them, if it can be shown to exist, may be a nullity
for any one of several reasons.
They may suddenly disappear if you ever do try to bring an action against them.
The cost of bringing an action may exceed the amount in dispute.
In short and simple - you've done your money.
Goes without saying that you should always choose a registered breeder
operating a properly established business.
-----------------------------------------
* You're thinking "But, K-Mart..."
That's different. They do change-of-mind retruns
as a choice of business practice, not because the law requires it.
** And that's why people sue each other over contract disputes all the time.
And why lawyers get asked to examine, comment, and advise on, the terms of contracts.