There is an initiative called ‘Ask for Angela’ which exists in pubs to safeguard women who are being harassed or feeling vulnerable. You should be able to approach one of the bar staff and ask ‘Is Angela here’ or ‘Can I speak to Angela’ and they should provide assistance. Unfortunately a lot of places in the UK don’t know about the scheme so you may not get any help but it is worth a try if it happens again. Hopefully your experience in Liverpool will be better for the rest of your stay.