How good is your word?
Does your word carry weight? That is, when you say, “I'll take care of it,” how truthful is the statement?
Do you mean that the job will be done in a reasonable time-frame?
Or that after months of delay, you’ll finally get around to it?
Or that it will get done only after you’ve been reminded multiple times?
If it’s anything but the first scenario, don’t be surprised when people aren’t eager to hear you say, “I’ll take care of it.”