You don't have to be paying interest on the item on your Kohl's card, first. You could have paid the item off in full. Second, as a jewelry associate at Kohl's, I can tell you that I am specifically instructed to tell customers that it will take no less than 8 weeks to get a ring sized. There are, of course, times of the year where it will take less time and rings may come back in 3 weeks. However, Mother's Day, Christmas, Valentine's Day, etc are all WICKED busy times for jewelry and that means lots of rings to be sized. For future reference, you can order the size you need online and only have to wait for shipping time, not sizing time.
I'm sorry that you've had to wait so long for your ring, but the associate should have told you up front how long you would have to wait. I can tell you that I would usually be the last one to defend the company because they don't treat their employees well, but I will tell you that it's not Kohl's fault your ring has taken so long to be sized. Do your research and post a complaint against the company that actually does the work. Since you said the ring was over $900, I know that you didn't have to even pay for your ring to be sized, so don't complain about the time it's taking. You wouldn't want the company doing the work to rush through every job and have awful quality work would you? Even if it meant getting your ring back in four weeks versus 8???