Lease agreement breach by leasing agent

Signed a lease agreement with them that was signed by the Landlord after negotiations and then three months down the line they amended the agreement costing me more than what my original agreement stated. Even after renegotiation they are still adding additional cost. They listed me on ITC for not paying the account but no invoicing has been sent to me after the first three months. Even after numerous correspondence I still do not have any invoicing or satisfactory agreement solution. They are rude in their way of dealing with their tenants. I will not recommend them to any prospective tenants.