help - semen quality

Hi. This seems like a good place to ask for cattle related advice. I had a bull collected and sold some of it. Have not heard from everybody but some have had good success. 5 claimed poor success. 2 reported poor conception of less than 20%. One bred 7 heifers twice with zero stuck. One used 10 straws with zero sticks so I sent 10 more free and they worked OK. One did not get any to stick but only bred a handful. 2 customers had the straws checked. 1 checked OK and it worked for them. The other check was subpar and that is a concern. I contacted the collection guy but he is not being very cooperative. They re-checked some of the semen and said that the semen would work but they will not send the results and do not want to do anything else. Have spoken to the owner and some employees. I also asked if they could have another lab re-check the straws at my expense but they ignored me. I am not satisfied. Anyway that I could force them to have it re-checked by somebody else? If any turn out to be bad should I expect a refund? What else can be done? Anybody experienced this before? Help!         

some questions to ask.

how many straws are left?

ask for an example semen analysis from other vendors

what were the options to dilute, ie flush quality etc.

there should be very specific numbers on semen quality.  if not, you don't need to do business there unless they cost less.

if you are going to sell semen,you should have specifics on the quality.

many more questions to ask.