I sent the company a chat describing the problem and asking if they had longer legs or even a CAD diagram of the legs to get a set printed.
1.
Do you need all four legs longer? Or just the front two? If just two, take the back legs, flip them up-side-down and bolt and/or glue them to the front legs. Done.
If you just bolt them, you can restore them to their original use, just with a hole in the foot. If you glue them, you can cut them to whatever length you need if they are too long.
OR
2.
If you need all four, commandeer four Lego blocks of the correct length and shape from your kid's closet, and bolt and/or glue those onto the four existing feet.
OR
3.
Fish around in the specialty hardware drawers at your local big box store for nylon nuts and bolts. Drill holes in the bottom of the existing feet to accept the bolts, and fasten them with the nuts. If you get if working like you want, put a drop of glue on the nut to lock it in place. The nylon nuts tend to work themselves loose if left on their own.
You can use the nylon nuts and bolts for the first two ideas, too. That avoids any corrosion issues. Or if you can't find them long enough for idea #3, then you might have to go with stainless steel.
Lots of ways to skin that cat without the trouble of fabricating something. By attaching something to the existing feet, they'll still be easily removable.
OR...
When support doesn't give you the answer you want, call them back to get someone else on the phone (instead of "asking for the manager"). You might get someone else more helpful/knowledgable/sympathetic. 'dude is right, most service departments encourage call volume (saves staff/money), which means doing what they can to get you off the phone, instead of turning you over to someone else. You'd be surprised how often a second (or third) call works.
But it's possible the call center can't supply parts. They sell what they get from their asian manufacturer, and they may not have access to parts.
Keep in mind that by extending the legs you are creating a longer lever, which will apply more lateral force to the legs and their sockets. Consider what might happen if the unit gets slammed into a step or the skimmer opening, either by an untimely gust of wind or a playful kid. Can they take that extra stress?