Money from share sales not received.

I phoned Computer Share on 26th November to sell my shares. There was some confusion as to what bank account was registered in my name, but eventually it was sorted, shares sold and I received a reference number. I live in the UK so was prepared for the transfer to take a while, but when the money was still not through by 10 December I phoned again. Again the agents seemed confused about the bank details but eventually assured me I would have the money by the 12th. It is now the 18th and I still do not have my money. Again I have made numerous calls (7 to be exact) and get cut off while on hold. Eventually I have been told that they will phone me back (not for the first time) with information about Income tax before they can transfer the money. Why is this the first time I have heard about tax problems? Why did they not get back to me when the money was unable to be transferred? As these shares have now been "sold" they are no longer receiving interest, what has happened to my money?