Literary agents

In UK, it's almost impossible to submit a manuscript to publishers without going through an agent, on the contrary of what is happening in France where publishers have a strong aversion for agents and wish to deal directly with the author. So of course I am looking for an agent for my novel. Two months ago I sent the first three chapters to 2 publishing houses willing to accept unsolicited manuscripts. These were USBORNE and Chicken House. USBORNE answered very quickly (a week) with a standard rejection letter and I still haven't heard anything from Chicken House. In the meantime I sent a synopsis and three chapters to a first agent with again a negative answer after less than a week. The second agent took a month to say no with a letter that was not even stating my name or the title of the manuscript. Strangely since I live near Edinburgh, I went there to check the address of this second agency and found out their office was TO LET! I guess I was not very lucky in my choice...