BEWARE ! No Date change possible at this Theater

I wanted to my tickets to another date - not cancel , but a week later. a 100% penalty fee was in order to change the date. This is apparently on the computicket website. I have often needed to change tickets for other computicket shows - this is the first time that a financial penalty applies ALL theater *****s, be aware of the strict rules at Theater on the bay I phone to asked the reason for the cost- but no apparent reason other than "these are our rules"