How can we get the existing client contact details

[#1]

Hi,

Please guide us to get one of our client details to whom we are trying to reach from last 2 weeks.

Thanks. 

[#2]

re: "Please guide us to get one of our client details to whom we are trying to reach from last 2 weeks."

That is not how this works.

If you have a former client, then you may message her using the Upwork Messages tool.

If she does not reply, then it is because she does not have any interest in working with you or communicating with you at this time.

[#3]

That i am aware of you are not able to 'get client details' unless of course they give them to you. 

If your existing client has gone quiet for a couple of weeks then perhaps they are busy/on holiday/not interested in project at this time - dont spam them with messages, send just one so they know you are waiting and be patient.

If it is a past client, and they are not responding, then leave them alone and assume they are not interested. 

Either way - unless the client has given you contact methods to use then Upwork messaging is your only contact tool.

Regards

jon