It is quite common for offices to be rather untidy because there is always so much to store in an office and so little space. Another problem is that everyone who works in the office is always so busy with their own work that they rarely take the time to clean up. In some cases, these offices will hire external cleaners and this will help to keep the office hygienic and clean to an extent however, in terms of getting the paperwork and filing in order, the only people who can actually do this will be the office staff themselves as it takes knowledge of the paperwork in order to put them in order.
Use an extra day
The best way to do this is to use an extra day, possibly a public holiday or a weekend to bring all of your staff in to work, or even part of your staff if you feel this will be sufficient in exchange for lunch and treats while they help to get the office in order. This way, your business would not be losing money as it will be a holiday and many of your staff would be happy to come in on a holiday to help out in exchange for a delicious lunch and a fun day with their colleagues. You will need to buy some extra storage in the days prior so that your staff can sort your paperwork out and use the storing units to make the office less messy and to have a good space management.
You might be able to find storage facilities in Singapore at many office furniture shops which will be designed specifically for this purpose. You will need to instruct your staff to get rid of as much of the paper as possible and to try to digitize as much as possible by scanning them and filing them digitally.
For the future, you will need to implement rules in your office to make sure that it does not get to this again. Some such rules that you can implement are no print rules and no paper rules. This means that your staff will not be allowed to take print outs unless absolutely essential and that all processes in your office will need to be digitized. Your staff will need to get used to using the cloud for shared documents and emailing files to each other instead of taking print outs. You can make sure this happens by buying less printing paper for your office and requiring permission from you personally to replace printing paper.