Soft Serve IceCream Production problem

I have started A soft serve ice cream business in Ghana - West Africa. I am manufacturing the soft serve powder mix from local products and flavors. For vanilla I use Milk powder (!50g/Liter of 28%fat milk powder) plus 200g sugar/Liter plus CMC 8g/Liter and Guar Gum 2G/liter. The same for strawberry,and chocolate, except that for chocolate I add 70g/l of cocoa. The ice cream comes out of the soft serve machine very nice and very creamy, but after a while, the creaminess is gone, and you can feel tiny particles of ice in the ice cream. I need food technician who is expert in the manufacturing of soft ice cream and can convince me of that by his credentials. Also he has to know how to fix that problem and keep the soft serve creamy. Once I find him - we will continue from there.