How long for Credit after replacement?

Hi,

Having recently had my battery replaced for my mbp, I was charged for the new battery, and told that when i send the old defective one back, they will credit my account back.

I received the battery in feb, and was charged on that bill. It is now mid way through april, and I still have yet to receive credit for the battery that i have returned.

I'm just wondering, how long does it take for apple to credit my account? has anyone else experienced a long wait time?

thanks guys,

One last thing, I can't seem to find my UPS tracking number... I've spent the last 30min trying to find it, but all i can find is the original delivery sticker that came with it, but no sort of number to show that i mailed it...

is this going to be a problem?