I was using hit btc and they dont allow withdrawal to a bank account - I had to send back to Coinbase and then transfer to my bank account however Coinbase require a fee to setup the bank account..thats the only reason lol
Try kraken.com ? I've used them for euro SEPA transactions, and only paid 0.09 EUR fee per transaction. I can't check if they offer GBP withdrawals though, as my internet provider seems to have routing problems at the moment.
According to
https://support.kraken.com/hc/en-us/articles/360000382363-Fiat-currencies-available-on-Kraken, Kraken only offers 4 fiats currencies to withdraw to (EUR, USD, JPY and CAD).
But what about
cex.io ? They offer GBP withdrawals and are probably more reliable than a random person without a trust rating here.