Contracting - changed of owner ship

Hi , y property was managed with manage company and b.com contract was signed with them 

As we decided to manage it our own ,we requested fidr change.of ownership ,contract was signed .

First it took contracting deaprtnent 25 days to reply to change minor detail ,we did 

Now it's been 27 days ,and no reply ,we tried to call 10-15 timea, visit  b.com offices but nk solution nor reply . 

As a result Bcom can't now receive any bed booking ,and also we are hosting gudst for free (!!!!) As we didn't get paid for 2 months already (about 10-12k euro)

Please ,I would be happy for advise