How i can calculate one shiping cost instead of two if i have two carriers?

[giwrgos88]

Hello, basically I have two types of catalog groups one frozen foods and another one which are products whare are not frozen. 

 

Because of my carrier limits to some cities I cannot have one carrier for the frozen foods and foods which are not frozen.

Therefore I have created two clients group the one to have as a carrier the frozen products and the other one for the other group. Then on products which are frozen I'm selecting the carrier which is for frozen and for the products which are not frozen the other carrier. The issue that I'm having now is that the client has to pay both shipping costs if he put one frozen product and one that is not. Is there any way so I can calculate only one shipping instead of two, for example if the basket has frozen food inside to use only the carrier of frozen because the carrier that ships the frozen food can also ship products which are not frozen.

 

Thank you