You say that you have received complaint from the Team Leader on excess use of mobile during working hours. Before this you say that you had sent her warning mail. This is where lies the catch!
Your query is on counselling. However, be it noted that counselling preceding any warning letter or mail. Therefore, you could have sent this query before sending the mail. Secondly, any warning letter has to be issued by senior authority like General Manager, Vice President, Director etc. Being HR Generalist, why did you involve in sending warning letter? Is HR Generalist senior enough authority so that general staff takes warning letter seriously?
Anyway, talk to the team leader and find out why he/she is saying that the team member talking excessively on mobile phone? Find out her definition of "excess" and has it impacted team member's work in general and of department/section in particular.
Later call the team member and tell her about complaint. Remind her about your previous mail and ask her what administration is expected to do if she continues with her wayward behaviour. Obtain agreement from about her behavioural correction. Before completion of the meeting, tell her to summarise the contents of the meeting and tell her that she will be issued warning letter but this time it will from senior authority.
While issuing warning letter, take a printout on the company's letterhead and obtain signature on the photocopy. Preserve the photocopy in the employee file.
Earlier there was query on draft for issue of warning letter for video calls during working hours. I had given the draft. Click the following link to refer it:
30th November 2017 From India, Bangalore
I really appreciate your all the suggestions. They are worthwhile, constructive and rewarding.
I would like to say further that I am working in a small organization(I.T. Company), where Director is the only top level management, after him all the managerial/official issues are handled by me only, whether its warning mail, one to one HR meeting, counselling, grievance handling, employee engagement activity,performance appraisal, almost all HR activities are done by me. I do not understand if I am going right way or not.
Director sir only orders me. I am the one who has to implement all the works. So, yesterday I counselled that employee who had been using excess mobile phone.She accepted that she listens to song plugging ear phone during working hour. And assured me not to repeat it again.
I have already noted your suggestions sir, as I am looking forward for a job in MNC of any big reputed company,where I can learn more and more managerial works for senior HR Manager's post.
1st December 2017 From India, Delhi