Corrupted gear buffs

I believe you should look into buffs corruption gear gives. I received a buff from Vissions, it gave me 7% boost to versatility. Hence I got 28% versatility. From this I bought boots from AH, they gave a 9% boost. From placing these on my feet I lost 1% versatility. Either the Stormwind buff was wrong, or your math on the corruption is. This cost me hard earned money that your support system doesn’t seem to want to return, This is very dishonest and make me wonder why I even play this game any longer.