Post Office Connection Fee

Ok, so i set up my line with PO after advice from talk talk pointed me towards this better option. I had previously put an order in with BT but then realised that talk talk wouldn't be able to take over the line if i was in 12 month contract with BT. BT said my line was already active & would be activated without sending anyone out (but i cancelled this and went with PO). Despite me telling PO the line was active they said an engineer would have to come out - and that i may be subject to a £120 activation charge "why would i be charged this?" i asked - they said that it is when the line is NOT active, ie. an old or brand new line & that they would not be able to tell me the cost until the engineer came. She said if the line was active i probably wouldn't be charged anything. Engineer came, literally spent 30 secs in my flat and would you guess - the line is active. Engineer said there would be no cost for it. Couple weeks later my bill arrives from post Office - £105 activation fee!! Not happy.

I have spoken to PO who have forwarded the case to their billing dept to investigate - I said that I was mis-informed and was given the impression there would be no activation charge - they tried to tell me to just pay the whole bill and if sorted they would refund it at a later date...I think not, spoke to someone else who said just to pay the line rental and ignore reminders until the billing dept get back to me.

After a month of waiting for PO and for Talk Talk to take over my line im finally going live tommorow - this is the last thing I need..

Has anyone got any advice for when the billing team get back to me (and no doubt) tell me to get stuffed?

Cheers!