retail/restaurant and major phone answering problems...

So I've searched for and anything close to this issue but I'm just coming up with nothing and hoping to get some guidance. Now to start, I currently run 7 stores of identical/very similar business model and products/services (fried foods and other foods). The stores have been healthy for the last 5-6 years and I am at a point where I see that business is slowing down. We have introduced new menus with success but unfortunately have high employee turn over because we can only manage to hire minimum wage employees except for a select few in each store who we use as "shift leaders" and company rules and tradition seems to be getting lost. I am well aware that the stores have their limitations but we have seen a huge problem these days with answering phone orders.



This problem was typically irrelevant because the owners (my family) would almost always be at the stores to either direct someone to answer or answer it for the employees, but since we are spread thin with increasing amount of stores we have noticed a big part of a sales, the phone orders, is falling off the grid... hoping for any experiences that dealt with similar issues or any ideas you folks may have. Thanks!