Write a Letter of thanks.
I would like to thank you for the opportunity you have given me for an interview for the [Position, title and reference number]. I have learned a lot of new things about the company [Name].
This vacancy is right for me as I have the requisite experience and qualification needed for this job. I shall fulfill my duties with complete dedication and honesty.
In case you need any additional information kindly contact me on my (phone number). I shall look forward to your reply.