access to property

Tenancy Types and Management

i have a tenant that was put it under the social services dept for the local council, during this time she has developed a drug habit and lost her children and locked herslef in the house and i can't get in to the house or get any response from her in writing, visits or telephone( which have now been disconnected). The gas safety cert is now due, but i can't get without breaking in or changing the locks, i don't even know if she still lives there. I have contacted the social servcies but they aren't very helpful and i don't know what to do.