Borough Supermarket

My partner and I have been a regular visitors of this store for the past year. We alway come in with our small dog and buy drinks and other food bits. There has never been a problem so far until tonight. The man working at the counter shouted at us in front of customers and told us to leave with the dog. When I tried to explain we come in regularly with our dog, he talked over me and told us to leave.
Not only was it rude and embarrassing, it was very uneducated behaviour from him. As regular customers who spend their money in this shop, we don't expect to be treated in this way. It would be helpful if the staff knew their own store policies - Are dogs allowed or are they not allowed? It's very unprofessional for one employee to make up his own rules as he pleases and humiliate a loyal customer.