It is curious that the printer did not recognise 3 carts all at once.
Been there a few years ago, discovered that, and do not buy Canon again. My last two inkjets and a laser have been Brothers and I have been very satisfied, although the inkjets are not great at photo printing (which I do not do). I needed Brother support once and it was a good experience.
Canon 'Support' probably reads scripts that usually work, but they are not paid to 'help you' they are paid to go through the scripts that might help you.
Have to ask, as I expect Canon 'support' did. Did you buy original Canon inks or compatible inks? nb. Sometimes if you admit to compatibles some support is done with you. Sometimes compatibles vendors get batches with bad chips that will not register in a printer. Replacing the inks does not work unless from different batches.Bad chips are known but uncommon for compatibles and very rare for originals.
I presume you did all of the following, but for the thread:
Resetting printer memory:
1 Remove your new cartridge and replace it with the old one. Leave your printer and go and do something else for 10 minutes.
2 Replace the old cartridge with the new one again.These two steps alone often resolve the issue, so see if your printer now recognises your new cartridges. However, if you’re still having trouble…
3 Remove the new cartridge. Make sure you place it in a clean and safe place where the cartridge or the surface won’t be damaged.
4 Turn the printer off button using its power button
5 Unplug your printer at the wall. It’s important to do both steps 4 and 5 separately, as some printers can remain in sleep mode if you’ve only switched off the power button on the printer control panel. Leave your printer like this for about 10 minutes or so.
6 Plug your printer back in at the wall (but don’t press the power button just yet)
7 Insert your new cartridge
8 Press the power button on your printer
9 If no joy try removing all the inks and doing the above a single ink at a time
Considering there are a number of sources that quote printer life as 1-2 years you might not have a good chance claiming a printer of that 'price and quality' should last longer than it did, but you might get a sympathetic ear. The normal failures are mechanical or print heads, not failing to recognise inks, so you might focus on that aspect.