Is it wrong to get 10 ton of ready mix concrete tipped on my "friends" drive?

hes owed me 400 quid for 3 months now and its always tomorrow tomorrow ive know him 2 years and thought he was a good bloke, but now ive had enough...............10 ton of ready mixed concrete, is that over the top? hes away all next week, so it would be really set solid by the time hes back lol, your views please............??!!