Katana Tongue ripping out. Advice?

So the other day i was putting on my katana lace up that ive had since september and i was pulling on the tongue and it started ripping out. i dont think i was doing anything unusual or pulling very hard. has anybody had this problem before with any of the sportiva shoes that have that tongue part in them, like solutions or futuras?

should i just try and sew it back myself? think this qualifies under warranty?

i know some people who have had that happen with various shoes ... including sportiva nagos

a cobler can fix it fairly easily, but it should be covered under warranty

;)