Been at UPS 3 weeks now, no paycheck yet because they keep saying something is wrong with their system and us latest hires can't even clock in, doing preload (belt to car). Was at FedEx ground before this. Seems as if I'm working harder for less pay. Most times I can keep up with packages coming down the belt for the first few hours then I'll get slammed with a bunch of big heavy packages and to managers and supes get mad and yell about keeping up and not letting things go by. Had a few come to try and demonstrate but ended up not even being able to keep up with just the load going to one of my cars. Then they said I've only been loading at 100 pph which makes no sense considering I finish in about 4.5 or less hours loading 2 trucks that average 300 to 360 packages each. Any tips or advice for me?