Mass upload of contact points using webservice

Summary:

We have many existing customers for which contact points and contact responsibilty isnt updated.

Content (please ensure you mask any confidential information):

We have many existing customers for which contact points and contact responsibilty isnt updated.
Is there any REST or webservice to do the same?

We have to update dunning contact purpose

Version (include the version you are using, if applicable):

24c

Code Snippet (add any code snippets that support your topic, if applicable):