Toxic work place

So someone at my work has corona and is now self isolating(I live in the uk) I work in a retail shop, no one got told about this person having covid and we haven’t had a deep clean. I told them I wasn’t comfortable working there as I live with someone who is at high risk and I’ve been in contact with this covid person anyway so shouldn’t I be self isolating?

I phoned my work place and said I have to self isolate as I’m following the government guide lines and I’ve been in contact with a covid person but she said that I don’t and she wants me in and if I don’t come in I am letting everyone down 😕this has made me very uncomfortable and I do not want to go back as first they haven’t put enough safety measures in and secondly she was so rude to me.

I feel so bad for not going in but I serve about 200/300 people a day and if I have caught it then I will be spreading it