Check their lifetime warranty.  It is probably just on their cheap muffler.
Try someplace else.

If it's a small hole, the size of a quarter or less, a good welder can 'fill
it'. I do it all the time. Option 2 is to cut the exhaust and put a sleeve
over the bad section (autozone sells a nice selection of exhaust sleeves.
Option 3 is to buy a 'muffler repair wrap' somewhere like autozone and just
wrap the thing up with the insulating rap/goop/screen/cramps that come in
the kit.... although cat convertor generate a lot of heat.

Of coarse Midas wants a fortune to fix it. Don't ever go to a place like
that, not even for an inspection. Go find one of the smalltown, out of the
way but not-so-far away liitle shops owned by the guy who does all the work
himself.

i replace the flex tubes all the timeon all sorts of vehicles. call around for
a shop that does custom exhaust work