Educational path

Answer:
Since you have IT service delivery experience I would suggest to consider two streams for further capability development:
1. ISO - ISO 20000 is ISO standard in IT Service management. With ITIL Foundation certificate there is small delta you need to gain ISO 20000 Foundation certificate. Afterwards - e.g. Internal Auditor course and certificate
2. ITIL - there are various trainings (and certifications) in ITIL that will give you detailed knowledge in e.g. delivery of IT Services. So, check the content and decide your educational path.

The articles
" ITIL Certification Path – list of all available ITIL trainings, exams and certificates" https://advisera.com/20000academy/knowledgebase/itil-certification-path-list-of-all-available-itil-trainings/
"How personal certificates can help your company’s IT Service Management" https://adviser a.com/20000academy/blog/2017/04/18/how-personal-certificates-can-help-your-companys-it-service-management/
"New ITIL Practitioner Guidance book – what does this mean for your certification and implementation?" https://advisera.com/20000academy/blog/2016/08/30/new-itil-practitioner-guidance-book-what-does-this-mean-for-your-certification-and-implementation/