Do Kiwis say "collect" instead of "Pick Up"?

We do use both, however, I believe we use "pick up" a lot more often that we use "collect" we Kiwi's love our slang hahaha

Both are common. But I would probably tend to say pick up more often. Depends on the situation tho. Like i would say "rubbish collection day is Monday", but would "pick them up from the airport", and "pick up a parcel from the post office".

Maybe the older generation would say collect, but that's just me speculating.

From what I've heard it's a mixture of both - I use "pick up" the most when it comes to getting groceries and getting someone from say the airport or a party etc

We use both, slightly more often "pick up" but i prefer "collect"

Both are common and one may also say ,"I'm going to get", or even rarely heard though and usually if they are in a big hurry "I'm going to grab.

Both, they mean the same thing here and both are used