Regarding STYLE in FORMAL letter and report writing

Make sure you leave behind a CONTACT NUMBER for the recipient of the letter in case he or she needs to get back to you. 

There are many ways to put this gentle reminder across in your letter:

1. If you need any further clarification on the matter, do not hesitate to contact me at 62210376. 
2. If you need to contact me, kindly call at 61234567.  I will be happy to attend to you. 
3. For further information, kindly dial 67890123.  I will be most pleased to help you. 
4. Do not hesitate to contact me at 65741239 if you have any further questions. 
5. I am available at the following numbers:  45631728 or 98622807.  Please do not hesitate to contact me.
6. I might have left out details which you may need for your investigation.  Please feel free to contact me at 98765432.  I will be most happy to be of assistance. 
7. My contact number is 89971234.  I will be most happy to be of assistance to you should you need any further clarification with regard to the matter. 
8. Kindly note that I may be contacted at 98761234.  Please feel free to call if you need any further assistance.
9. Please be informed that I may be contacted at 78961234.  Alternatively, you may write to me at tampines@gmail.com.sg.
10. You can reach me at my handphone number - 65879012 or text me at 98881234.
11. I have tried my best to furnish this report.  However, should you need any further information, please do not hesitate to contact me at 76881234.  I am also reachable at my work place at 56781020.  Please ask for Samuel Lee when you call.  Thank you.