I had this problem the other day!
I failed to switch my taming gear on at the correct time while training Resists in Haven and spamming Follow messages and I lost my White Cu I worked so hard to obtain. I was human at the time. I had just finished training the White Cu to 100 Wrestling and was sitting at 30 Parry 60 Resists and also at just under the mark for 5 slots waiting to scroll him up.
ELITE and a few other very helpful people who hang in Haven tried to retame my pet for me but they all failed abysmally. ELITE eventually suggested that I revert back to Elf with a character token and even gave me some gold to purchase one. A very cool cat right there. I thanked him and got the token.
Got my White Cu back that was wondering the undead in Haven and had to put him away into stables to rebond him later this week. I was on the edge of my seat because this pet was near fully trained lol. It had 700HP and no one could seem to kill it or get its HP down low enough. If they did, it regen'ed quickly. I was glad to know I had a strong pet haha.
Ugh, anyway, talk about a huge fiasco and ordeal. But I recovered in the end. Lesson learned. I also intend on getting tame/lore to 120 w/real skills. Love the community these days! Thanks again peeps.