I really don't understand the table tennis racket incident

I feel like if they had just issued a refund, it would have quietly blown over.
Where on earth did they get the baseless confidence to insist it was worth 140,000 KRW?
By social standards, no one would think that a high-end professional sports product
would be sold for 140,000 KRW at a place like Alpha Stationery, which is more like a Daiso.
In fact, refusing to sell it at the fixed price in a large chain store that follows a fixed-price policy for all products,
and stubbornly refusing to issue a refund until the very end, is an all-time mystery.
This is a case where there is absolutely no room for neutrality; it's a 100% losing battle,
but why on earth?
Usually, in a controversy, there is always some room for mitigating circumstances for the other party,
but I truly do not understand this incident.