On arrival back at Heathrow T4 I rang the number I was instructed to but there was no reply. I called 12 times and eventually got a call back and was told to go to level 4 departures. There are only 2 levels as I discovered. I rang again and after another 5 attempts got through and they confirmed it was level 2 and to wait for the car. I waited for 40 minutes in the freezing cold and rang for an update but there was no reply to any of the 26 further phone calls I made. In all 43 phone calls, a lot of frustration and anger and a long delay. The poor bloke who dropped off the car was very polite and apologetic but it didn't make up for the overall poor and rather rude service.