I can only say such deductions are not lawful under Section 24 of the Employment Act and it may not solve the problem also. Such mistakes are quite serious and should be avoided. Try to device a better checking systems so that such mistakes can be avoided or reduced.
KL Siew has put up a sister site by the name of mylabourlaw.net, which is in effect a more user-friendly version of the present popular pesaraonline.net. The site is in the process of being fine-tuned but it is fully functional. You are invited to visit the website at http://www.mylabourlaw.net and give your views or suggestions. Queries can be posted and be responded from there as usual.