What is the best way to resolve the issue of maintenance complaint in a room , without disturbing the guest?

There are two types of complaints one if guest complaints about any issue and it dosnt disturb it means gust did nt have any big issue regarding that then do your maintenance when guest went out for any work or lunch ETC.

Second thing is when guest complaints about any issue and he/she is really disturbing it then you have to solve the issue on spot by excusing the guest

We should take permission from guest,inform him before starting any process and maximum we can suggest him another room.

When finish we can send him a Thank you letter with a compliment.

But if we donot have any other empty room and the complaint will take long ,, so what will we do then ..? 

Thank you for the invitation, I agreed with the rest of the answers