Did not get Rank: Premium?

Hello. I've tried reaching out through a ticket but unfortunately, to no avail.

I've donated a sum of 10 euro via mobile with a few separate donations in order to get a premium rank so that I can skip queue however I'm still a regular. I would like to know how much exactly do I have to donate in order to acquire a premium status? I'd like to know exactly if it has to be a singular donation or can it be acquired by donating a few separate times as it's very inconvenient. Thank you in advance for your answer.

Regards,
tisar