Hi,
From the attached screenshot, I can see that you are still viewing the Ticket as a call center agent, and not as a Service Technician.
Please refer the suggested business roles and corresponding work center assignments for a Service Technician.
Refer section 5.3.5.1 Recommended Business Roles and Work Center Assignments for SAP Cloud for Customer, in the administration guide here - http://help.sap.com/saphelp_sapcloudforcustomer/en/PDF/EN-2.pdf
Once you assign the correct work center, and remove the Customer Service - Queue, you will see a different UI for the work ticket, where you will be able to perform the actions.
Regards,
Venki