1. I only collected the PO xxx from the customer ABC last Friday
2. I only collected the PO xxx last Friday from the customer ABC
1...Do you mean that you only collected the PO xxx (and nothing else), or that you didn't collect the PO xxx until last Friday?
2...I think you mean the second one. If so, you can say...
a) I didn't collect the PO xxx from the customer ABC until last Friday.
b) I collected the PO xxx from the customer ABC only last Friday.
c) (Only last Friday)(Not until last Friday) did I collect the PO xxx from the customer ABC.
Your #2 choice is better than your #I choice but your meaning still isn't totally clear, and I wouldn't wouldn't separate "PO xxx" and "from the customer".