HELP: My weapon from +7 become +6

Hi Divine Survivors of I am Legend,

About 1 month ago, I logged in and tried to enchant my weapon.

I always use Level down protection and Enchant Disability protection on my weapon

Somehow when I tried to enchant my weapon, it went from +7 to +6. -.-"

Is there anyway I can have it back to at least +7? Since I use level down protection it should not drop back to +6..

Please help me, survivors of DivineSouls!

Saradon,

And my IGN is Saradon.