Att active on community

Can a tenant be denied services in an active on community. This means Att is already installed for the whole complex and each unit has a router and account number attached to it and no other service provider can service this complex because of the type of contract had between the property and Att. Tenants are supposed to be able to call and pick a service plan and put in their name for their unit and move on but that’s been an issue on my end.