As each call was completed you could automatically schedule the next phone call activity (via workflow) for 10 or 30 days from then (which might give the best customer experience). (Alternatively you could set up a recurring workflow. Would suggest the other option as it's simpler).
Setting up workflows is simple. They can be set up at a systems level (Go to Settings>Customizations>Customize the System>Processes>Workflow)
or by a user (under Settings>Processes>New>Workflow> select Phone Call).
Give the Call Subject a name e.g. Regular Customer Care Call. [Optional: You may want to add a field to the Phone Call Activity entity e.g. "Auto-generated" checkbox (so that only those ones drive another callback).]

Click on OK, Make the scope Organisation (or Business Unit if it only applies to your team). Start when Record Status Changes.
Add steps to check conditions e.g.
Check that the Phone Call is Activity Status = 'Completed'; that the Topic = 'Regular Customer Care Call'
Add step to Create Phone Call
Auto set the properties of the new record = e.g. Subject = 'Regular Customer Care Call'



You can create/update a phone call activity record at any time to make a note of what you have talked with the customer about. This can be done really quickly from the Social Pane>Activities tab.
With workflow and/or CTI integration these activities can be created automatically on outbound or inbound calls as required.
If you want a voice-recording of the call then normally you would do a CTI integration and have the calls tracked in a specialised call database (which could have links to it from CRM to get to the actual recording). However if the calls were short you could potentially capture 5-10MB voice files into CRM.
You can see which calls are outstanding/needing to be made by looking at a dashboard. They will appear in your list of activities.
When the calls are automatically scheduled (via workflow) they can be allocated e.g. the person who made the last call, a particular service team, or the owner/manager of the customer.
Your dashboard can be set up to show a list of customers to call (that is relevant to you / your team). On your dashboard you can also show charts of numbers of calls overdue / numbers of calls due each day for the next week etc.
OOTB Dashboards are available, but if they don't highlight what you want then you can create your own system views and charts (or personal views and charts) and use them to put together your own system dashboards or personal dashboards). Have a look at the OOTB dashboards (under Sales>Dashboards) or if they aren't what you want then try this video as a starting point.
www.youtube.com/watch