I hate my job but can't find a new one.

Hi everyone
I am a long time reader of boards but a first time poster. Basically as the title say's I really do not like my job, I work in retail which is not the problem at all as I have always worked in retail and I usually quite enjoy it, The problem is that the company I work for treat their staff like crap and work us like dogs. Take last night for example for the first two hours of my four hour shift I was put on tills which o.k no one likes but everyone has to do, come six o'clock a manager comes to me and say's there is five pallet's of stock to go out a display to be remerchandised and two sections that you have to face off for tomorrow and it has to be done before you finish at eight. I could get the five pallets done in two hours I could even face off my sections and maybe have five minutes to spare to get the display sorted, I could do all this if the shop was closed and I didn't have a bell going off every two minutes for me to jump onto the till and relieve a large que. I don't mind hard work and I never have but this kind of stuff has been happening since the day I started and that would be all good and well because I was showing the managers that I am worth investing in and that if a promotion oppurtunity came along that I was the man for the job. But that will not happen anytime soon because since I started one year ago there has been three different managers and three different assistant managers. Every time I get somewhere I have to start again with someone new. Also last night I was brought a form to sign saying I clocked out fifteen minutes early from my four hour shift last Monday I remember Monday quite well I told my manager I would be clocking out two minutes early because I had to catch a bus that left at four, I live in abbeyleix and the bus from portlaoise is once every two to three hours and my little girl was in her grandmothers so I really needed to catch that exact bus. I left exactly two minutes early I worked ten minutes past my shift the two days after but there was no mention of this on the form which I brought up and was fobbed off. I know my grammar is appalling so I apologise if anyone is still reading. I have recently been sending c.vs out to other companies and I haven't got so much as a call back from anyone and it is realy getting me down, I am not going to quit the job that I have as much as I dislike it because I don't want to join the dole que I was there for long enough. I guess in between this rant I am really just wondering if anyone has any advice on how I might find a new job. Again I am sorry for my awful awful grammar.