You should head to the official singer repair center in dubai. They are the only authorized repair center here and I have had good experience with them.
You should be able to look up the exact address from the singer website but I think it was salahuddin road or something somewhere near all the embassies.
Minimum 100 dhs would be charged for having a look at it and then further more for any parts needed etc but it won't be much. I have had no trouble after my last repair 4 yrs ago.
They open on Saturday ..you drop it one week and would most probably get it back next week.
Hope that helps.