Our church place is in a business center also registered as a company which during the week we use it as a school to help support the church. Some brothers thinks this is wrong because Jesus attacked the moneychangers at the temple. What do you think?

We must ask Why did Jesus attack the moneychangers?  How was it a "den of thieves"?  What was he attempting to achieve by attacking the financial nucleus of the corrupt temple system?

I believe he was symbolically attacking and criticizing the establishment--the corrupt priesthood with its decadence and valuing money over people. (The Pharisees loved money, Jesus once commented.) Do you think he would have kicked over a table where students sold pies to support education or forbidden money ever to exchange hands (e.g. registering for a church event)? I doubt it.