A mortiking in a suit walks by and hands you a Morty Card! i just got this card, please, what can i do with? tysm for help...^^

If you use it, it'll give you an 1% increase on your bank interest for 1 month. :)
aah... i got this mezz every day -- Your extra bank interest has run out.. what it means?? there is no link on it... tysm for answering so kindly..:)... ღ(ˆ◡ˆ)ღ

those messages are for the daily 1% bonus for collecting your interest every day, but they go out at the wrong times. You can just ignore them
- Do you know if the Morty cards actually work now?
there's some more information on this thread. Apparently, the interest is supposed to be capped at 3% (with a Morty card) and they're not expiring like they're supposed to either.