The Letting Centre

The inventory we received stated that the property had a working phone line. However, after speeking to BT they have confirmed that they will be a charge of £130 to re-connect the phone line to the property (due to an engineer having to come out ). They have also stated that we do not have a working phone line. The letting agency have stated that as the property has a terminal on the wall this constitutes a working phone line.

What is the best course  of action to challenge this legally? Thanks