I ordered a package on the 7th and it was supposed to come today but it hasn't arrived.

[lau-9373]

I ordered a package on the 7th and it was supposed to arrive today but it hasn't arri yet.

[**peaseblossom**]

You need to give it more time and the day hasn't finished yet.   You won't be able to start a "not received" case until the latest estimated delivery date on the listing has passed.  

After that time if you still don't have it select "Report an item you didn't receive" on here:
https://www.ebay.co.uk/help/buying/returns-items-not-received-refunds-buyers/get-help-item-hasnt-arr...
and escalate it 3 complete working days later to get a full refund.

[plpmr]

but you only created this account today.