I still cannot track my packages even tho both sellers said they sent them

I ordered two things from aliexpress, from different sellers on different days. I have tracking numbers but they can't be tracked, website says "tracking number invalid". I ordered one on 4-20-15 and the other on 4-21-15. Seller A said item was shipped on 4-21 and Seller B said item was shipped 4-22. I contacted the sellers 4-29-15 for the "real" tracking numbers and they both say the items have been shipped but won't give me the tracking numbers. Why can't I track them still? (RC348625741CN) and (RI326801234CN) are the tracking numbers given to me. Should I wait a couple more days for tracking to be updated?