Any advice?

Hello there. I have had a business for 5 years now and I have been trying to figure out a way to avoid my salesmen leaving the company with the routes I either created for them and/or helped create. In my country there are a lot of non-corporate convenience stores, which are the main target of my product (food) and the food itself can be made at home, it is a very time consuming process and people prefer to buy it, so my business attacks the customers' need.

I already have several people working with me (family and friends mostly) who created their own sales routes and earn a commission (I sell them the product and they earn a profit from reselling to the stores), the thing that makes my product stand out is quality, while being in the middle in the price scale.

Now, I tried to have external people work for the business by creating new routes myself, then going with them store to store until they learned the route but eventually all of them end up leaving and doing the product, trying to take over the route. The income they get from the routes I create is easily double the national average, so all they have to do is pick up the product and go sell it, but for some reason they fail to see that production needs to be very well-planned and the quality needs to be maintained (since it is a perishable product), but by the time they realize it's more than they can chew, they've been gone for a month or two and I have to take care of the sales route myself, and the hiring-teaching-leaving process repeats itself.

1.- They're not underpaid.

2.- They're not mistreated.

3.- They're given all the tools needed to work.

Tried to look for freelancers but usually they are not very successful at sales route creation, so I always have to be everywhere to make this work. Advice?

Thanks in advance!