lousy retention tactics / disrespect

I have a Layby with this shop in festival mall, paid half of the amount for my sons sneakers, he saw something else he likes online we got that instead and every time we try to cancel this layby we told that the till does not have a lousy R600. I don't know if this is a tactic to keep the sale or just plain disrespect. the inconvenience of going to this shop for the R600 and all the calls is tedious. senior management needs to better equip their stuff with skills of customer services because this is an inconvenience. I will never again shop in this store nor advise any of my friend to shop here. I'm disgusted. 2 weeks same story no money in the till. at this rate they are running at a loss and shouldn't even afford rent in the mall.