Is this letter appropriate?

Dear Sir,

In relation to your letters ref. 58R-GP, dated 14th Jun 1, and 60R-GP, dated 17th June 14, please note our responses respectively as follows:

1- We could not configure (a) which docs you are referring to and (b) the relation between the quality of finishing works and your approval on these documents? Could you please clarify?
Meanwhile, please be reminded that we perform all our activities and carry out works in our scope always based on Employer approved documentation (i.e. drawings). Further, for your convenience and clarity purposes, we refer you to the part of Employer’s response letter on the drawings issue, dated 16 Jun 2014.
2- Please provide substantiating reasons behind of your rejection and instruction to stop the subject work activity.
- If it is related with any defect exists in the work done or any dissatisfaction on the workmanship, we would immidiately take necessary precautions to make good of both defect and the workmanship. We do not see any necessity to stop the work activity.
- If it is related with your intention of changing the approved design in place, then we seek for an official request from the Employer in this extent with enough details upon which we will study the impacts and shared with you. Once we agree on the variation order, then we will do all necessary arrangements to implement the changes.
3- With regard to your direction for the new drawings, this is a matter of new desicion to be made by the Employer and conveyed to us on their letterhead.
4- Your recommendation is noted against which we kindly refer you to our responses above. However, your threatening approach for payments was just disregarded in a real attempt of which you will bear the consequences.

Thank you in advance