If you want to control the frequency of limits that your customers receive, you will want to set their survey limits in Settings.  Important:  Please note that when you set the survey limit via "Settings", you will only be setting up survey limits for all new surveys going forward.  If you want to set survey limits for existing customers, you will need to use Bulk Actions in the  Client menu.

Here is a step by step as to how to set survey limits for all new surveys entered from that point:

1.  Settings (drop down arrow on top right, next to your company's name).

2.  Scroll down to Survey Limit.

3.  Choose your survey limit.

Choosing this limit again makes the change for all new customers created.  If you need to change the frequency of a specific customer, you can do so in the customer's profile And again, if you wan to change all past customers, you would do so using Bulk Actions in the Client menu.  Here is a support article with a step by step: How to change current clients' survey frequency.