Cheapest way to call EU mobile numbers now that Skype is dead?

I make a call to EU phone numbers around 2x a month, for 10-15 minutes each time. I used to use Skype's PAYG option, but this has been killed off with no warning at the end of last year. Now Skype wants me to buy a monthly plan, which I don't want to do as it costs around 5-8x my usual monthly spend with their PAYG rates, and they don't even offer one for the specific countries I usually need to make calls to. What's the best alternative out there currently?