Inserting using multiple contexts into LocalDB

I've written this ActionResult to model an Order that goes through. I couldn't think of another way to write this without using context Db<Sets>. It runs kinda slow, taking around 4 seconds to complete. Is there way to optimize the code or is this kinda has to happen since I'm doing so many inserts?

public ActionResult New(CustomerOrderModel model)
{
    ViewBag.LimitNotExceeded = checkLimit();
    if (ModelState.IsValid)
    {
        int prepaid;
        int userIdLoggedIn = WebSecurity.CurrentUserId;
        try
        {
            //
            //Add Customer
            using (var ctx = new CustomerContext())
            {
                ctx.CustomerInfos.Add(model.CustomerModel);
                ctx.SaveChanges();
            }

            //
            //Add Order
            model.OrderInfo.UserProfileUserID = userIdLoggedIn;
            model.OrderInfo.Customer_id = model.CustomerModel.id;
            model.OrderInfo.DateCreated = DateTime.Now.ToLocalTime();
            using (var ctx = new OrdersContext())
            {
                ctx.OrderInfos.Add(model.OrderInfo);
                ctx.SaveChanges();
            }

            //
            //Add Code
            key = "s121sd";
            KeyCode TheKey = new KeyCode();
            TheKey.code = key;
            TheKey.Customer_id = model.CustomerModel.id;
            TheKey.nif = model.CustomerModel.nif;
            TheKey.UserProfileUserId = userIdLoggedIn;
            TheKey.DateCreated = DateTime.Now.ToLocalTime();
            using (var ctx = new CodesContext())
            {
                ctx.CodesInfos.Add(TheKey);
                ctx.SaveChanges();
            }

            //
            //Assign and Create debts
            using (var ctx = new UsersContext())
            using (var dbx = new DebtsContext())
            {
                prepaid = ctx.UserProfiles.Find(userIdLoggedIn).Prepaid;
                if (prepaid > 0)
                {
                    --prepaid;
                    string query = "UPDATE dbo.UserProfile SET Prepaid='" + prepaid + "' WHERE UserId='" + userIdLoggedIn + "';";
                    ctx.Database.ExecuteSqlCommand(query);
                }
                else
                {
                    Debts NewDebt = new Debts();
                    NewDebt.paid = false;
                    NewDebt.DateCreated = DateTime.Now.ToLocalTime();
                    NewDebt.UserProfileUserId = userIdLoggedIn;
                    NewDebt.Order_id = model.OrderInfo.id;
                    dbx.DebtInfos.Add(NewDebt);
                    int debts = dbx.DebtInfos.Count(q => q.UserProfileUserId == userIdLoggedIn);
                    if (debts <= ctx.UserProfiles.Find(userIdLoggedIn).MaxDebt)
                    {
                        //
                        //Warn them when they reach their last
                    }
                    dbx.SaveChanges();
                    string query = "UPDATE dbo.UserProfile SET Prepaid='" + prepaid + "' WHERE UserId='" + userIdLoggedIn + "';";
                    ctx.Database.ExecuteSqlCommand(query);
                }
            }
            //DateTime a = DateTime.FromBinary(model.OrderInfo.Timestamp);
            return RedirectToAction("Index", "Home");
        }

        catch (DataException ex)
        {
            ViewBag.ChangeResult = ex;
            ModelState.AddModelError("", "Unable to save changes. Try again, and if the problem persists see your system administrator.");
        }
    }
    return View(model);
}