Kohler Rialto Pressure Lite

The seals on the tank resrevoir seem to have broken or seperated, causing the toilet to overflow. Have any of you heard of this? Should I replace the toilet or are their repair parts available. The toilet is about 10 years old. I also don't know whey the overflow did not stop this from flooding????

If the inside tank looks like this, there are no parts.

Rialto Pressure Lite

It looks like the black cannister (reservoir?) cracked. Have other people had this problem? Is Kohler offering any credits or something???

Kohler customer service may be able to help.

Most of these tanks are quite old now.
They haven't sold this type for years.