What reasonable to expect of tenant during viewings?

I gave 3 months notice to my landlord, now with one month to go viewings have started on the property. I was aware viewings would happen at some stage but the first I heard of it was when someone phoned me to say they were coming to film the flat that day for online estate agent. I was already on my way to work and as he had keys didn't feel like I could refuse. Since then I have had phone calls from several different agencies asking to view the flat, some with keys, some without.
After getting sick of getting so many calls throughout the day I asked the LL to provide a list of names and numbers of everyone who he has given my details to, he came back with a list of 7 agencies but didnt have the numbers. I then arrived home to all the lights being left on so it was obvious someone had been in the flat, when quering this with the landlord he replied with "apparently agent x was around."
This was almost the last straw until one night getting ready to go out and half undressed an agent with two tenants walk into my flat. The agent told me the LL said the property was vacant!
I have tried to be as accomodating as possible, but am now thinking about not answering any calls from agents. Any advice? Am I obliged to arrange these viewings?
Sorry for the long post!