mmm what would you say, me still classing myself as a greenhorn as only been in the game a year, i have had various work from a agency that seem ok , but listen to this an see what you think, i work for the same client reguarly no probs, however this shift i am offered 4am start class1 to wales an back, fair enough. i turn up at the site 3.30am told no trucks goin they all gone maybe its at our other site, i drive there 4 miles, then told no not here and told to go home, i get back to bed after being out 1-1/2 hours for nothing, then fone the agency an tell them what happened at 9am, then i get a call at 1pm askeing if i will go at 2pm, i say no i been up too long and would be too tired and had a drink also so no. they say they will put in 8 hours for me, but whether they will pay it is another thing. anyway a month later i never got a bean, my longtime driver friends tell me the agency wouldve got the money from the client and they have kept it! do you agree and what should i do about it? 
If they work the same as most other agencies that I’ve read about on this site then you are legally entitled to 8 hours pay for that day - ask the agency where your money is, verbally first (keep it friendly as it could be a genuine oversight) and then in writing if needs be.
First write them a letter explaining that you want paying within 7 days or you will sue them in the small claims court. If you suffer from a lack of work from them due to your potential court action then you will claim future earnings from them.
If they don’t pay sue them. 
Might be worth asking the company if they paid the agency also. As you’ve worked for them regularly I’m sure they’d be interested.
yep i will go there tomorow when i finish, my trouble is i am too polite till i lose it then get myself in trouble, i think they may see this as a nice little earner my wages an their bit on top, this was 3 weeks ago now so not too long i hope, i will be polite and say i have been told this by various proffessionals in the game. i am not worried about them being funny as i have a permanent job that i decided not to tell them about just incase the 1st week didnt go well, but i think i still wont tell them untill the outcome of this, if i dont get my money i may name an shame them , but that may put me out of any future work with them? if ever required. but i dont like being turned over. i know business is business but not at my expense
The fact that there was no truck at your first job,is not your problem.You turn up in good faith,and then go home,they should pay you,although I would have rung them as soon as I was leaving,to keep them in the picture,and cover your arse.It matters not that you ring at 4am to tell them,after all,they work on a 24 hour basis.I know,I work as an agency driver as well.Or if you wanted to,you could have sent a text,which may have been better,as there is then a record of it.They want to thank YOU,for not claiming the extra mileage as well!!! 
As for the 2nd job,well if you did that,you should be paid 8 hours for that as well,as they would have been paid by that client.
Just a word of warning,finally.
If you go to a job,and this happens,make out a timesheet,and get the customer to sign it,and make a note on the timesheet what happened.Mark on your 8 hours,and keep a copy for yourself,after you have sent the agency theirs.That way you have a cast iron record,should it go nasty.
Speak to them first,then if you get no reply,write to them,but be polite about both approaches.
Ken.
Most agencies have a member of staff on call 24/7 with a mobile number,any problems,call them immediately!