bad attitude & service

I Am a small construction company , I buy a lot at builders, the cement is at a good price, I am currently buying around 60 bags a day. ever time, time is wasted with bad attitude from the loaders staff & supervised staff. we land up loading our cement ourselves. I have called on management things get done but I have to get them every time. the loaders are lazy, 6 people doing one mans work. I alone, load double of the cement bags than of 4 loaders.