Tenants installed cable - what to do about BT reconnection

Tenancy Deposits

I noticed about a year ago that my tenants had broken and then removed the telephone I bought for the property. Next, I noticed that they had had cable installed and were using a cable phone. I've read stories in the papers about reconnection to BT being very expensive if the supplier has been changed in the past. Now that my tenants are moving on, should I worry about the new tenant facing such a high connection charge? Can I take a sum out of the security deposit to discount this for him/her? I realise that my new tenant might not even want BT and be quite happy with cable, but I'm wondering if returning the property as let is an issue here (I'm already facing a huge dispute about damage this couple have done to my property, but this is something that just occurred to me).