For the people who don't have Ancestry data:
Download DNAStudio(
here) and convert your raw data to the Ancestry. Open your converted raw data with notepad+, press ctrl+a, and ctrl+c. Create a new excel file and press ctrl+a and ctrl+v. You will be able to edit columns. Delete the column which allele2 written, copy the column which allele1 written and paste it to the column which you have just deleted and edit its name as allele2. Save it as .csv file (not xlsx) and exit the excel. Open the same file with notepad+, press ctrl+f and replace ; with 3 times of "space". Save the file again as .csv and it should be ready to upload Gedmatch. Then do the same process for allele2.
At least this is how i did it and it worked fine. Probably won't be precise as much as Ancestry testers though.